Sheet for ink jet recording, ink for ink jet recording, manufacturing method of ink for ink jet recording, ink set for ink jet recording, and ink jet recording method

ABSTRACT

An ink for ink jet recording, which hardly causes blotting of an image even under high humidity conditions while maintaining the advantages as water-based ink (handling properties, stability, producing properties, hue), is provided. Also provided is a method of manufacturing ink for ink jet recording, an ink set for ink jet recording, and an ink jet recording method.

This is a divisional of application Ser. No. 10/660,653 filed Sep. 12,2003. The entire disclosure of the prior application, application Ser.No. 10/660,653, is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a sheet for ink jet recording, an inkand ink set for ink jet recording excellent in the durability of animage under high humidity conditions, and to an ink jet recordingmethod.

BACKGROUND OF THE INVENTION

With the rapid expansion of information technology industry in recentyears, various information processing systems have been developed, andrecording methods and recording apparatus suitable for these informationprocessing systems have also been developed and put to practical use.

Of these recording methods, an ink jet recording method has been widelyused not only in offices but also in homes from the advantages thatrecording is possible on various kinds of materials, hardware(apparatus) is relatively inexpensive, compact, and excellent inquietness.

With the achievement of high resolution of the ink jet printer in recentyears, it becomes possible to obtain printed matters of so-calledphotograph-like high image quality, and with the advancement of hardware(apparatus), various kinds of recording sheets for ink jet recordinghave been developed.

The characteristics required of the recording sheet for ink jetrecording generally include that (1) a drying speed is quick (the inkabsorption speed is high), (2) the diameter of an ink dot is appropriateand uniform (free of blotting), (3) graininess is good, (4) theroundness of a dot is high, (5) color density is high, (6) saturation ishigh (free of lackluster), (7) the water proofness, light fastness andozone resistance of a print part are good, (8) the brightness of arecording sheet is high, (9) the storage stability of a recording sheetis good (yellowing discoloration is not brought about even in long termpreservation, an image is not blurred under long term preservation(blurring due to aging hardly occurs)), (10) a sheet is difficult to bedeformed and dimensional stability is good (curling and dimensionalchange are sufficiently small), and (11) the traveling performances ofhardware are good (e.g., smooth feeding of sheets).

Further, in the use of photo-glossy paper used for obtaining a printedmatter of so-called photograph-like high image quality, the recordingsheet is also required to have glossiness, a surface smoothness, and aphotographic paper-like touch analogous to that of a silver saltphotograph in addition to the above various characteristics.

Sheets for ink jet recording using a coloring material-receiving layerhaving a porous structure are developed and put to practical use inrecent years with the intention of the improvement of the above variouscharacteristics. Such ink jet recording sheets are excellent in inkreceptivity (a quick drying property) and have high glossiness due tothe porous structure.

For example, JP-A-10-119423 (the term “JP-A” as used herein means an“unexamined published Japanese patent application”) and JP-A-10-217601suggest a sheet for ink jet recording comprising a support havingprovided thereon a coloring material-receiving layer containing fineinorganic pigment particles and a water-soluble resin and having a highporosity.

These sheets for recording, in particular, ink jet recording sheetsprovided with a coloring material-receiving layer comprising a porousstructure in which silica is used as the inorganic pigment fineparticles are excellent in ink absorption due to their structure, haveink receptivity capable of forming an image of high resolution, and havehigh glossiness.

However, a coloring material-receiving layer having a porous structurehas two problems. In relation to the fact that a trace amount of gas inthe air, in particular ozone, causes the discoloration of a printedimage with the lapse of time, one problem is that a printed image issusceptible to discoloration by ozone gas in the air, since a coloringmaterial-receiving layer having a porous structure has many pores.Accordingly, recording materials having a coloring material-receivinglayer of porous structure are required to have resistance against ozonein the air (ozone resistance). Another problem is that blotting of inkis great by printing, since a coloring material-receiving layer having aporous structure has many pores. It is strongly demanded to solve theformer problem mainly by the improvement of inks from the viewpoint ofthe development of fast coloring materials, and to solve the latterproblem by the improvement of recording sheets.

In addition to the above, since many kinds of inks contain water-solubledyes from various necessary conditions, such as operationcharacteristics, the defect that a printed image is liable to blot underhigh humidity conditions is also promoted from this aspect.

As ink jet recording methods, a method of pressurizing ink by a piezoidand discharging ink droplets, a method of generating bubbles in ink byheat and discharging ink droplets, a method of using ultrasonic waves,and a method of sucking and discharging ink droplets by electrostaticforce are known. As the ink compositions for these ink jet recordingmethods, water-based inks, oil-based inks and solid inks (a meltingtype) are used. Of these inks, water-based inks are mainly used from thepoints of handling properties, odor and safety.

Colorants for use in the inks for these ink jet recording methods arerequired to be high in solubility in a solvent, capable of high densityrecording, good in hue, fast to light, heat, air, water and chemicals,good in fixing ability to image-receiving materials and not liable toblot, excellent in storage stability as inks, nonpoisonous, high inpurity, and available inexpensively. However, it is extremely difficultto find out colorants which satisfy these requirements on high levels.Various kinds of dyes and pigments have been suggested and brought intopractical use for ink jet recording, however, a colorant which satisfiesall of these requirements is not found yet under the present conditions.In conventionally well-known dyes and pigments attached with color indexNos. (C.I. Nos.), those which sufficiently satisfy necessarycharacteristics required of the ink for ink jet recording including hueand fastness have not been found yet. The development of dyes andpigments having good hue and fastness as the colorants for ink jetrecording has been advanced aggressively, but, additionally, thesolution stability and dispersion stability of ink are also importantcharacteristics concerning the stable operation of apparatus and thestorage stability of ink.

With respect to this point, although water-soluble dyes are substitutedwith water-soluble groups and these water-soluble groups are excellentin the point of their contribution to the stability of water-solubledyes in water-based ink, water-soluble groups also have a weak pointthat they are liable to cause blotting of recorded images, and imagesformed are liable to blot under high humidity conditions when the numberof water-soluble groups of dyes and pigments is increased for improvingthe stability of ink. Therefore, there is a problem of incompatibilityof the stability in ink with blotting resistance.

SUMMARY OF THE INVENTION

The present invention has been done based on the above background, andan object of the present invention is to provide a sheet for ink jetrecording which hardly blots even under high humidity conditions,especially to provide a sheet for ink jet recording which hardly blotseven when an image-receiving layer has a porous structure.

The another objects of the present invention are to provide an ink forink jet recording which hardly causes blotting of an image even underhigh humidity conditions while maintaining the advantages as water-basedink (handling properties, stability, producing properties, hue), amanufacturing method of the ink for ink jet recording, an ink set and anink jet recording method.

As a result of eager investigation to solve the above problems, thepresent inventors have found that a betaine compound having a specificstructure and a compound capable of taking a betaine structure caneffectively prevent blotting of an image, and the above problems havebeen solved on the basis of the discovery. That is, the presentinvention was achieved by the ink jet recording sheets, the ink and inkset for ink jet recording, and the ink jet recording method described inthe followings.

1. A sheet for ink jet recording, comprising:

-   -   a support; and    -   a coloring material-receiving layer containing a mordant and a        compound represented by the following formula (1):        (R_(k))_(p)—N-[L_(m)-(COOM_(n))_(q)]_(r)  (1)        wherein R represents an alkyl group, an aryl group or a        heterocyclic group; when a plural number of Rs are present, the        plurality of Rs may be the same or different; at least two of a        plurality of R's may be linked with each other to form a cyclic        structure; L represents a divalent or higher linking group; M        represents a hydrogen atom, an alkali metal cation, an ammonium        ion, an organic amine cation, or a negative ion sign; q and r        each represents an integer of 1 or more; k and m each represents        0 or an integer of 1 or more; n represents an integer of 1 or        more; p represents 0 or an integer of 1 or more; (p+r) is 3 or        4, and when (p+r) is 4, the N atom represents a quaternary        ammonium cation and one of the M's represents a negative ion        sign.

2. The sheet for ink jet recording as described in the item 1, whereinat least one of R and L in the formula (1) contains a hydrocarbon grouphaving 8 or more carbon atoms.

3. The sheet for ink jet recording as described in the item 1 or 2,wherein the coloring material-receiving layer further contains awater-soluble resin.

4. The sheet for ink jet recording as described in the item 3, whereinthe water-soluble resin is at least one resin selected from the groupconsisting of polyvinyl alcohol resins, cellulose resins, resins havingan ether bond, resins having a carbamoyl group, resins having a carboxylgroup, and gelatins.

5. The sheet for ink jet recording as described in any one of the items1 to 4, wherein the coloring material-receiving layer further contains afine particle.

6. The sheet for ink jet recording as described in the item 5, whereinthe fine particle is at least one fine particle selected from the groupconsisting of silica, colloidal silica, alumina and pseudo-boehmite.

7. The sheet for ink jet recording as described in the item 3, whereinthe coloring material-receiving layer further contains a crosslinkingagent capable of crosslinking the water-soluble resin.

8. The sheet for ink jet recording as described in any one of the items1 to 7, wherein the coloring material-receiving layer is a layerobtained by crosslinking a coated layer of a coating solution containinga fine particle, a water-soluble resin and a crosslinking agent, and thecrosslinking is performed by applying a basic solution having a pH valueof 8 or more to the coated layer, in which the application of the basicsolution is performed (1) simultaneously with the coating of the abovecoating solution, or (2) in the middle of a drying of the coated layerof the coating solution and before the coated layer showsfalling-rate-drying.

9. The sheet for ink jet recording as described in any one of the items1 to 8, wherein the compound represented by the formula (1) is acompound represented by the following formula (2):R-N-(L-COOM)₂  (2)wherein R, L and M each has the same meaning as described in item 1.

10. The sheet for ink jet recording as described in the item 7, whereinthe crosslinking agent is a boron compound.

11. An ink for ink jet recording, which comprises a dye, water, awater-miscible organic solvent and a compound represented by thefollowing formula (1):(R_(k))_(p)—N-[L_(m)-(COOM_(n))_(q)]_(r)  (1)wherein R represents an alkyl group, an aryl group or a heterocyclicgroup; when a plural number of Rs are present, the plurality of Rs maybe the same or different; at least two of a plurality of Rs may belinked with each other to form a cyclic structure; L represents adivalent or higher linking group; M represents a hydrogen atom, analkali metal cation, an ammonium ion, an organic amine cation, or anegative ion sign; q and r each represents an integer of 1 or more; kand m each represents 0 or an integer of 1 or more; n represents aninteger of 1 or more; p represents 0 or an integer of 1 or more; (p+r)is 3 or 4, and when (p+r) is 4, the N atom represents a quaternaryammonium cation and one of the M's represents a negative ion sign.

12. The ink for ink jet recording as described in the item 11, whereinat least one of R and L in formula (1) contains a hydrocarbon grouphaving 8 or more carbon atoms.

13. The ink for ink jet recording as described in the item 11, whereinthe compound represented by the formula (1) is a compound represented bythe following formula (2):R-N-(L-COOM)₂  (2)wherein R, L and M each has the same meaning as described in item 11.

14. The ink for ink jet recording as described in any one of the items11 to 13, wherein the dye includes a compound represented by thefollowing formula (1):

wherein A represents a 5-membered heterocyclic group;

B¹ and B² each represents a nitrogen atom, ═CR¹— or —CR²═, and wheneither one of B¹ and B² represents a nitrogen atom, the other represents═CR¹— or —CR²═; R⁵ and R⁶ each represents a hydrogen atom, an aliphaticgroup, an aromatic group, a heterocyclic group, an acyl group, analkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, analkylsulfonyl group, an arylsulfonyl group or a sulfamoyl group, and thehydrogen atom of each substituent may be substituted;

G, R¹ and R² each independently represents a hydrogen atom, a halogenatom, an aliphatic group, an aromatic group, a heterocyclic group, acyano group, a carboxyl group, a carbamoyl group, an alkoxycarbonylgroup, an aryloxycarbonyl group, a heterocyclic oxycarbonyl group, anacyl group, a hydroxy group, an alkoxy group, an aryloxy group, aheterocyclic oxy group, a silyloxy group, an acyloxy group, acarbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxygroup, an amino group, an acylamino group, a ureido group, asulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonylgroup, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclicsulfinyl group, a sulfamoyl group or a sulfo group, and the hydrogenatom of each substituent may be substituted;

R¹ and R⁵, or R⁵ and R⁶ may combine to form a 5-or 6-membered ring.

15. The ink for inkjet recording as described in any one of the items 11to 14, wherein the dye includes a compound represented by the followingformula (I):

wherein X₁, X₂, X₃ and X₄ each represents —SO—Z, —SO₂—Z, —SO₂NR₁R₂, asulfo group, —CONR₁R₂ or —CO₂R₁; Z represents an alkyl group, acycloalkyl group, an alkenyl group, an aralkyl group, an aryl group or aheterocyclic group, which are substituted or unsubstituted; R₁ and R₂each represents a hydrogen atom, an alkyl group, a cycloalkyl group, analkenyl group, an aralkyl group, an aryl group or a heterocyclic group,which are substituted or unsubstituted; when a plural number of Zs arepresent, the plurality of Zs may be the same or different; Y₁, Y₂, Y₃and Y₄ each represents a monovalent substituent; when a plural number ofX₁s, X₂s, X₃s, X₄s, Y₁s, Y₂s, Y₃s or Y₄s are present, the plurality ofX₁s, X₂s, X₃s, X₄s, Y₁s, Y₂s, Y₃s or Y₄s may be the same or different; Mrepresents a hydrogen atom, a metal atom, or an oxide, hydroxide orhalide thereof; a₁ to a₄ and b₁ to b₄ each represents the number ofsubstituent X₁, X₂, X₃, X₄, Y₁, Y₂, Y₃ or Y₄, and a₁ to a₄ eachrepresents an integer of 0 to 4 but all of a₁ to a₄ are not 0 at thesame time; b₁ to b₄ each represents an integer of 0 to 4.

16. A concentrated ink composition comprising a dye, water, and acompound represented by the following formula (1):(R_(k))_(p)—N-[L_(m)-(COOM_(n))_(q)]_(r)  (1)wherein R represents an alkyl group, an aryl group or a heterocyclicgroup; when a plural number of Rs are present, the plurality of Rs maybe the same or different; at least two of a plurality of R's may belinked with each other to form a cyclic structure; L represents adivalent or higher linking group; M represents a hydrogen atom, analkali metal cation, an ammonium ion, an organic amine cation, or anegative ion sign; q and r each represents an integer of 1 or more; kand m each represents 0 or an integer of 1 or more; n represents aninteger of 1 or more; p represents 0 or an integer of 1 or more; (p+r)is 3 or 4, and when (p+r) is 4, the N atom represents a quaternaryammonium cation and one of the M's represents a negative ion sign.

17. The concentrated ink composition as described in the item 16, whichcomprises the compound represented by the formula (1) in an amount offrom 0.001 to 30 wt %.

18. The concentrated ink composition as described in the item 16 or 17,which comprises the dye in an amount of from 0.01 to 50 wt %.

19. A method for manufacturing an ink for ink jet recording, whichcomprises manufacturing the ink by using the concentrated inkcomposition as described in any one of the items 16 to 18.

20. An ink set for ink jet recording, which comprises the ink for inkjet recording as described in any one of the items 11 to 15.

21. An ink jet recording method which comprises recording an image byusing the sheet for ink jet recording as described in any one of theitems 1 to 10.

22. An ink jet recording method which comprises recording an image byusing the ink for ink jet recording as described in any one of the items11 to 15 with an ink jet printer.

23. An ink jet recording method which comprises recording an image byusing the ink set as described in the item 20 with an ink jet printer.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is described in detail below.

The ink jet recording sheet in the present invention contains a compoundrepresented by formula (1) in a coloring material-receiving layer.

In the first place, a compound represented by formula (1) is described.A compound represented by formula (1) is a betaine compound containing acarboxyl group and a nitrogen atom and having surface activity, and acompound capable of taking a betaine structure.

Ink for use in the ink set in the present invention comprises a dyedissolved in water or an organic solvent. The ink is preferably awater-soluble ink comprising a water-soluble dye.

The ink for ink jet recording in the present invention is characterizedin that it contains a betaine type compound represented by formula (1).That is, although the ink is water-based ink, blotting of ink of aprinted matter is effectively prevented by containing a compoundrepresented by formula (1). Further, since even a dye or a pigmenthaving a great number of water-soluble groups which generally causeblotting of ink can be used in the ink without causing blotting, thestability of ink can be improved and the hue of a printed image can bemaintained or improved.

Concentrated ink is ink in which the concentration of a dye or a pigmentis made higher than the concentration of the dye or the pigment in theink in a working state for convenience of transportation and handling,or for profitability, and working ink can be prepared by diluting withwater or liquid for dilution obtained by excluding the dye, the pigmentand one or more other components from the ink composition.

In formula (1), R represents an alkyl group (preferably an alkyl grouphaving from 1 to 20 carbon atoms which may be substituted, e.g., methyl,ethyl, propyl, butyl, hexyl, octyl, dodecyl, cetyl, stearyl and oleyl),an aryl group (preferably an aryl group having from 6 to 20 carbon atomswhich may be substituted, e.g., phenyl, tolyl, xylyl, naphthyl, cumyland dodecylphenyl), or a heterocyclic group (preferably a heterocyclicgroup having from 2 to 20 carbon atoms which may be substituted, e.g.,pyridyl and quinolyl), and they may be linked with each other to form acyclic structure. An alkyl group is particularly preferred.

L represents a divalent or higher linking group. As the examples of suchlinking groups, divalent or higher linking groups containing an alkylenegroup or an arylene group as a fundamental constitutional unit arepreferred. Heteroatoms, e.g., an oxygen atom, a sulfur atom and anitrogen atom, may be contained at the linking principal chain part.

R and L may be substituted with various substituents. The examples ofthese substituents include, e.g., an alkyl group (an alkyl grouppreferably having from 1 to 20, more preferably from 1 to 12, andparticularly preferably from 1 to 8, carbon atoms, e.g., methyl, ethyl,isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl,cyclopentyl and cyclohexyl), an alkenyl group (an alkenyl grouppreferably having from 2 to 20, more preferably from 2 to 12, andparticularly preferably from 2 to 8, carbon atoms, e.g., vinyl, allyl,2-butenyl and 3-pentenyl), an alkynyl group (an alkynyl group preferablyhaving from 2 to 20, more preferably from 2 to 12, and particularlypreferably from 2 to 8, carbon atoms, e.g., propargyl and 3-pentynyl),an aryl group (an aryl group preferably having from 6 to 30, morepreferably from 6 to 20, and particularly preferably from 6 to 12,carbon atoms, e.g., phenyl, p-methylphenyl and naphthyl), an amino group(an amino group preferably having from 0 to 20, more preferably from 0to 12, and particularly preferably from 0 to 6, carbon atoms, e.g.,amino, methylamino, dimethylamino, diethylamino, diphenylamino anddibenzylamino), an alkoxyl group (an alkoxyl group preferably havingfrom 1 to 20, more preferably from 1 to 12, and particularly preferablyfrom 1 to 8, carbon atoms, e.g., methoxy, ethoxy and butoxy), an aryloxygroup (an aryloxy group preferably having from 6 to 20, more preferablyfrom 6 to 16, and particularly preferably from 6 to 12, carbon atoms,e.g., phenyloxy and 2-naphthyloxy), an acyl group (an acyl grouppreferably having from 1 to 20, more preferably from 1 to 16, andparticularly preferably from 1 to 12, carbon atoms, e.g., acetyl,benzoyl, formyl and pivaloyl), an alkoxycarbonyl group (analkoxycarbonyl group preferably having from 2 to 20, more preferablyfrom 2 to 16, and particularly preferably from 2 to 12, carbon atoms,e.g., methoxycarbonyl and ethoxy-carbonyl), an aryloxycarbonyl group (anaryloxycarbonyl group preferably having from 7 to 20, more preferablyfrom 7 to 16, and particularly preferably from 7 to 10, carbon atoms,e.g., phenyloxycarbonyl), an acyloxy group (an acyloxy group preferablyhaving from 2 to 20, more preferably from 2 to 16, and particularlypreferably from 2 to 10, carbon atoms, e.g., acetoxy and benzoyloxy), anacylamino group (an acylamino group preferably having from 2 to 20, morepreferably from 2 to 16, and particularly preferably from 2 to 10,carbon atoms, e.g., acetylamino and benzoylamino), analkoxycarbonylamino group (an alkoxycarbonylamino group preferablyhaving from 2 to 20, more preferably from 2 to 16, and particularlypreferably from 2 to 12, carbon atoms, e.g., methoxycarbonylamino), anaryloxycarbonylamino group (an aryloxycarbonylamino group preferablyhaving from 7 to 20, more preferably from 7 to 16, and particularlypreferably from 7 to 12, carbon atoms, e.g., phenyloxycarbonylamino), asulfonylamino group (a sulfonylamino group preferably having from 1 to20, more preferably from 1 to 16, and particularly preferably from 1 to12, carbon atoms, e.g., methanesulfonylamino and benzenesulfonylamino),a sulfamoyl group (a sulfamoyl group preferably having from 0 to 20,more preferably from 0 to 16, and particularly preferably from 0 to 12,carbon atoms, e.g., sulfamoyl, methylsulfamoyl, dimethylsulfamoyl andphenylsulfamoyl), a carbamoyl group (a carbamoyl group preferably havingfrom 1 to 20, more preferably from 1 to 16, and particularly preferablyfrom 1 to 12, carbon atoms, e.g., carbamoyl, methylcarbamoyl,diethylcarbamoyl and phenylcarbamoyl), an alkylthio group (an alkylthiogroup preferably having from 1 to 20, more preferably from 1 to 16, andparticularly preferably from 1 to 12, carbon atoms, e.g., methylthio andethylthio), an arylthio group (an arylthio group preferably having from6 to 20, more preferably from 6 to 16, and particularly preferably from6 to 12, carbon atoms, e.g., phenylthio), a sulfonyl group (a sulfonylgroup preferably having from 1 to 20, more preferably from 1 to 16, andparticularly preferably from 1 to 12, carbon atoms, e.g., mesyl andtosyl), a sulfinyl group (a sulfinyl group preferably having from 1 to20, more preferably from 1 to 16, and particularly preferably from 1 to12, carbon atoms, e.g., methanesulfinyl and benzenesulfinyl), a ureidogroup (a ureido group preferably having from 1 to 20, more preferablyfrom 1 to 16, and particularly preferably from 1 to 12, carbon atoms,e.g., ureido, methylureido and phenylureido), a phosphoric acid amidogroup (a phosphoric acid amido group preferably having from 1 to 20,more preferably from 1 to 16, and particularly preferably from 1 to 12,carbon atoms, e.g., diethylphosphoric acid amido and phenylphosphoricacid amido), a hydroxyl group, a mercapto group, a halogen atom (e.g.,fluorine, chlorine, bromine and iodine), a cyano group, a sulfo group, acarboxyl group, a nitro group, a hydroxamic acid group, a sulfino group,a hydrazino group, an imino group, a heterocyclic group (a heterocyclicgroup preferably having from 1 to 30, and more preferably from 1 to 12,carbon atoms, and the hetero atoms include a nitrogen atom, an oxygenatom and a sulfur atom, e.g., imidazolyl, pyridyl, quinolyl, furyl,thienyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl,benzothiazolyl, carbazolyl and azepinyl), and a silyl group (a silylgroup preferably having from 3 to 40, more preferably from 3 to 30, andparticularly preferably from 3 to 24, carbon atoms, e.g., trimethylsilyland triphenylsilyl). These substituents may further be substituted. Whenthere are two or more substituents, they may be the same or different,and they may be linked with each other to form a ring, if possible. Thecases where a plurality of structures represented by formula (1) arecontained via R or L are also included in formula (1).

M represents a hydrogen atom, an alkali metal cation (e.g., a sodiumion, a potassium ion, a lithium ion and a cesium ion), an ammonium ion(in the case of a quaternary ammonium salt, the ammonium ion representsa quaternary nitrogen cation, e.g., a tetramethylammonium ion, atetraethylammonium ion, a trimethylbenzylammonium ion, amethylpyridinium ion, and a benzylpyridinium ion), an organic aminecation (i.e., a nitrogen cation of a quaternary amine salt, e.g., aquaternary nitrogen cation of protonated methylamine, dimethylamine,ethylamine, diethylamine, triethylamine, diaza-bicycloundecene,diaza-bicyclo-octane, piperidine, pyrrolidine, morpholine,N-methylpiperidine, N-methyl-morpholine, pyridine, pyrazine, aniline,and N,N-dimethyl-aniline), or a negative ion sign. A plurality of M's inthe same molecule may be the same or different. An alkali metal ion anda hydrogen atom are preferred.

q and r each represents an integer of 1 or more; k and m each representsan integer of 0 or more; n represents an integer of 1 or more; and prepresents an integer of 0 or more, wherein p+r is 3 or 4, and when p+ris 4, the N atom represents a quaternary ammonium cation, and one of theM's represents a dissociated anion.

It is preferred that a hydrocarbon group having 8 or more carbon atomsbe contained in R or L, and a compound represented by the followingformula (2) is most preferably used.R—N-(L-COOM)₂  (2)wherein R and L each has the same meaning as described above. Rparticularly preferably represents an alkyl group, and L preferablyrepresents an alkylene group.

The preferred examples of compounds represented by formula (1) in thepresent invention are shown below, but the invention is not limitedthereto.

The compound represented by formula (1) of the present invention is usedin an amount of from 0.0001 to 10 g/m² of an ink jet recording sheet,preferably from 0.001 to 5 g/m², and particularly preferably from 0.01to 2 g/m². When coating solutions for two layers are used for coating anink jet recording sheet, the compound may be added to either layer, butit is preferred to add the compound to the uppermost layer coatingsolution from the viewpoint of coating property.

A compound represented by formula (1) is contained in the ink in theinvention in an amount of from 0.01 to 20 wt %, preferably from 0.1 to10 wt %, and more preferably from 0.5 to 5 wt %.

The sheet for ink jet recording of the present invention is described indetail below.

When the compound represented by formula (1) in the present invention isadded to a coloring material-receiving layer, for the purpose ofincreasing the affinity with water, the compound may be added as themixture with a water-soluble organic solvent, e.g., an alcohol compound(methanol, ethanol, isopropyl alcohol, ethylene glycol, diethyleneglycol, diethylene glycol monobutyl ether, polyethylene glycol,polypropylene glycol, glycerol, diglycerol, trimethylolpropane, ortrimethylolbutane), an ether compound (tetrahydrofuran or dioxane), anamide compound (dimethyl-formamide, dimethylacetamide, orN-methylpyrrolidone), or a ketone compound (acetone).

When the compound represented by formula (1) in the present inventiondoes not have sufficient water solubility, the compound may be added asthe mixture with a hydrophobic organic solvent, e.g., an ester compound(ethyl acetate, dioctyl adipate, butyl phthalate, methyl stearate, ortrirecsyl phosphate), an ether compound (anisole, hydroxyethoxybenzene,hydroquinoneordibutyl ether), a hydrocarbon compound (toluene, xylene,or diisopropylnaphthalene), an amide compound (N-butylbenzenesulfonamideor stearic acid amide), an alcohol compound (2-ethylhexyl alcohol,benzyl alcohol or phenethyl alcohol), a ketone compound(hydroxyacetophenone, benzophenone or cyclohexane), or with theabove-described water-soluble organic solvent. The addition may beperformed by oil droplet dispersion, latex dispersion, solid dispersionor polymer dispersion.

Water-Soluble Resin:

In the ink jet recording sheet in the present invention, it is preferredfor the coloring material-receiving layer to contain a water-solubleresin together with the compound represented by formula (1) of theinvention.

As the examples of the above water-soluble resins, polyvinyl alcoholresins having a hydroxyl group as the hydrophilic constitutional unit[polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol,cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol,silanol-modified polyvinyl alcohol, and polyvinyl acetal], celluloseresins [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethylcellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose(HPC), hydroxyethylmethyl cellulose, and hydroxypropylmthyl cellulose],resins having chitins, chitosans, starch, or an ether bond [polyethyleneoxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG), andpolyvinyl ether (PVE)], and resins having a carbamoyl group[polyacrylamide (PAAM), polyvinyl pyrrolidone (PVP) and polyacrylic acidhydrazide] can be exemplified.

In addition to the above, polyacrylate, maleic resin, alginate andgelatins having a carboxyl group as the dissociating group can also beexemplified as water-soluble resins.

Of the above resins, polyvinyl alcohol resins are particularlypreferred. The examples of the polyvinyl alcohol resins are disclosed inJP-B-4-52786 (the term “JP-B” as used herein means an “examined Japanesepatent publication”), JP-B-5-67432, JP-B-7-29479, Japanese Patent No.2537827, JP-B-7-57553, Japanese Patent Nos. 2502998, 3053231,JP-A-63-176173, Japanese Patent No. 2604367, JP-A-7-276787,JP-A-9-207425, JP-A-11-58941, JP-A-2000-135858, JP-A-2001-205924,JP-A-2001-287444, JP-A-62-278080, JP-A-9-39373, Japanese Patent No.2750433, JP-A-2000-158801, JP-A-2001-213045, JP-A-2001-328345,JP-A-8-324105 and JP-A-11-348417.

As the examples of water-soluble resins other than polyvinyl alcoholresins, the compounds disclosed in JP-A-11-165461, paragraph Nos. [0011]to [0014] are also exemplified.

These water-soluble resins may be used alone or in combination of two ormore.

The content of the water-soluble resin of the present invention ispreferably from 9 to 40 wt % based on the total solid content mass ofthe coloring material-receiving layer, and more preferably from 12 to 33wt %.

Fine Particles:

In the ink jet recording sheet in the present invention, it is furtherpreferred for the coloring material-receiving layer to contain awater-soluble resin and fine particles together with the betainesurfactant of the invention.

A porous structure can be formed by adding fine particles to a coloringmaterial-receiving layer, thus the ink absorption performance of thelayer is improved. In particular, when the solid content of fineparticles in the coloring material-receiving layer is 50 wt % or more,more preferably 60 wt % or more, it becomes possible to obtain a betterporous structure, as a result, an ink jet recording sheet havingsufficient ink absorption performance can be obtained. Here, the solidcontent of fine particles in the coloring material-receiving layer isthe content computed on the basis of the components in the compositionconstituting the coloring material-receiving layer excluding water.

Organic and inorganic fine particles can be used as such fine particles,but it is preferred to use inorganic fine particles from the point ofink absorption and image stability.

As the organic fine particles, polymer fine particles obtained byemulsion polymerization, micro-emulsion polymerization, soap-freepolymerization, seed polymerization, dispersion polymerization andsuspension polymerization are preferably used, e.g., powders, latex oremulsion-state polymer fine particles of polyethylene, polypropylene,polystyrene, polyacrylate, polyamide, silicone resin, phenol resin, andnatural high polymer are exemplified.

As the inorganic fine particles, e.g., silica fine particles, colloidalsilica, titanium dioxide, barium sulfate, calcium silicate, zeolite,kaolinite, halloysite, mica, talc, calcium carbonate, magnesiumcarbonate, calcium sulfate, pseudo-boehmite, zinc oxide, zinc hydroxide,alumina, aluminum silicate, calcium silicate, magnesium silicate,zirconium oxide, zirconium hydroxide, cerium oxide, lanthanum oxide andyttrium oxide are exemplified. Of these inorganic fine particles, silicafine particles, colloidal silica, alumina fine particles andpseudo-boehmite are preferred from the viewpoint of capable of forminggood porous structures. These fine particles may be used as primaryparticles as they are or may be used in the state of the secondaryparticles formed. The average primary particle size of these fineparticles is preferably 2 μm or less, and more preferably 200 nm orless.

Silica fine particles having an average primary particle size of 20 nmor less, colloidal silica having an average primary particle size of 30nm or less, alumina fine particles having an average primary particlesize of 20 nm or less, and pseudo-boehmite having an average pore radiusof from 2 to 15 nm are more preferred, and silica fine particles,alumina fine particles and pseudo-boehmite are particularly preferred.

In general, silica fine particles are classified roughly into wetprocess particles and dry process particles (a gas phase process)according to their manufacturing processes. In the wet process, aprocess of forming an active silica by acid decomposition of silicate,appropriately polymerizing, aggregating and precipitating the activesilica, thereby obtaining hydrous silica is mainstream. On the otherhand, in the gas phase process, a process by gas phase thermalhydrolysis (flame hydrolysis) of silicon halide, and a process ofreduction gasification of silicious sand and cokes on heating in anelectric furnace by arcs, and oxidizing the product with air (an arcprocess), thereby obtaining anhydrous silica are mainstream. “Gas phaseprocess silica” means anhydrous silica fine particles which is obtainedby the above gas phase process. As the silica fine particles for use inthe present invention, gas phase process silica fine particles areparticularly preferred.

The above gas phase process silica differs from hydrous silica in thedensity of silanol groups on the surface and the presence or absence ofvoids and shows different properties, and the gas phase process silicais suitable for forming a three dimensional structure having a high voidratio. The reason for this is not clearly known but, in the case ofhydrous silica, the density of silanol groups on the surface of aparticle is as many as from 5 to 8/nm², and so the silica fine particlesare liable to aggregate densely. On the other hand, in the case of thegas phase process silica, the density of silanol groups on the surfaceof a particle is as few as from 2 to 3/nm², and the fine particles areliable to flocculate sparsely, and so it is presumed that a structurehaving a high void ratio is formed.

Since the gas phase process silica has an especially large specificsurface area, the absorption and retentivity of ink are high, andfurther, since it has a low refractive index, transparency can be givento a coloring material-receiving layer by performing dispersion untilparticles reach suitable particle sizes, and so high color density and agood coloring property can be obtained. The fact that a coloringmaterial-receiving layer is transparent is important not only in thecase where transparency is required, e.g., OHP, but in the case of beingapplied to a sheet for recording, e.g., a photo-glossy paper, in thepoint of obtaining high color density and a good coloring glossiness.

The gas phase process silica preferably has an average primary particlesize of 30 nm or less, more preferably 20 nm or less, particularlypreferably 10 nm or less, and most preferably from 3 to 10 nm. Theparticles of the gas phase process silica are liable to attach to eachother due to hydrogen bonding by silanol groups, thus a structure havinga high void ratio can be formed when the average primary particle sizeis 30 nm or less, and an ink absorbing characteristic can be effectivelyimproved.

The silica fine particles may be used in combination with theabove-described other fine particles. When the gas phase process silicais used in combination with the above other fine particles, the contentof the gas phase process silica in all the fine particles is preferably30 wt % or more, and more preferably 50 wt % or more.

As the inorganic fine particles for use in the present invention,alumina fine particles, alumina hydrate, and the mixtures and compositesof these compounds are also preferably used. Of these compounds, aluminahydrate is preferred for well absorbing and fixing ink, andpseudo-boehmite (Al₂O₃·nH₂O) is especially preferred. Various forms ofalumina hydrates can be used, and it is preferred to use boehmite in asol state as the starting material for capable of obtaining a smoothlayer.

Pseudo-boehmite has an average pore radius of preferably from 1 to 30nm, and more preferably from 2 to 15 nm, and a pore volume of preferablyfrom 0.3 to 2.0 ml/g, and more preferably from 0.5 to 1.5 ml/g. Thesepore radius and pore volume are measured according to nitrogenadsorption desorption method, for example, they can be measured by a gasadsorption desorption analyzer (e.g., “Omnisoap 369”, a trade name,manufactured by Beckman Coulter, Inc.).

Of alumina fine particles, gas phase process alumina fine particles arepreferred for their large specific surface area. The average primaryparticle size of the gas phase process alumina is preferably 30 nm orless, and more preferably 20 nm or less.

When the above fine particles are used in a sheet for ink jet recording,they can also be used preferably in the modes disclosed, e.g., inJP-A-10-81064, JP-A-10-119423, JP-A-10-157277, JP-A-10-217601,JP-A-11-348409, JP-A-2001-138621, JP-A-2000-43401, JP-A-2000-211235,JP-A-2000-309157, JP-A-2001-96897, JP-A-2001-138627, JP-A-11-91242,JP-A-8-2087, JP-A-8-2090, JP-A-8-2091, JP-A-8-2093, JP-A-8-174992,JP-A-11-192777, and JP-A-2001-301314.

The water-soluble resins and fine particles mainly constituting thecoloring material-receiving layer of a sheet for ink jet recording inthe present invention may be used respectively alone or a plurality ofmaterials may be used as mixture.

From the viewpoint of maintaining transparency, the kind ofwater-soluble resin to be combined with fine particles, in particular,silica fine particles, is important. When the above gas phase processsilica is used, a polyvinyl alcohol resin is preferably used as thewater-soluble resin. Above all, polyvinyl alcohol resins having asaponification degree of from 70 to 100% is more preferred, andpolyvinyl alcohol resins having a saponification degree of from 80 to99.5% is especially preferred.

The polyvinyl alcohol resins have hydroxyl groups as the constitutionalunit, and the hydroxyl groups and the silanol groups on the surface ofthe silica fine particles form hydrogen bonding, therefore, a threedimensional network structure is easily formed with the secondaryparticles of the silica fine particles as the network chain unit. It isthought that a coloring material-receiving layer having a high voidratio and sufficient strength can be formed by the formation of thethree dimensional network structure.

In ink jet recording, a porous coloring material-receiving layerobtained as described above rapidly absorbs ink by a capillaryphenomenon, thus a dot free of blotting of ink and having high roundnesscan be formed.

Polyvinyl alcohol resins may be used in combination with theabove-described other water-soluble resins. When the polyvinyl alcoholresins are used in combination with the above other water-solubleresins, the content of polyvinyl alcohol resins in all the water-solubleresins is preferably 50 wt % or more, and more preferably 70 wt % ormore.

Content Ratio of Fine Particles To Water-Soluble Resin:

The ratio by weight of fine particles (x) to a water-soluble resin (y)[PB ratio (x/y)] greatly affects the film structure and the filmstrength of a coloring material-receiving layer. That is, when the ratioby weight (PB ratio) becomes great, the void ratio, pore volume andsurface area (per unit mass) become great, but the density and strengthare liable to lower.

As the ratio by weight [PB ratio (x/y)] in the coloringmaterial-receiving layer of the invention, from 1.5/1 to 10/1 ispreferred with the intention of preventing the reduction of filmstrength and cracking by drying due to excessively large PB ratio, andalso preventing the reduction of void ratio by clogging of voids withthe resin and the succeeding reduction of ink absorption due toexcessively small PB ratio.

On the other hand, it is necessary for a coloring material-receivinglayer to have sufficient film strength, since sometimes stress isapplied to a recording sheet when traveling through the carrier systemof an ink jet printer. It is also necessary for a coloringmaterial-receiving layer to have sufficient film strength to preventcracking and peeling of the coloring material-receiving layer by acutting process to sheets. Taking these cases into consideration, theratio by weight (x/y) is more preferably 5/1 or less (the case where thenumerical value before the mark “/” is decreased means “lower”), on theother hand, from the viewpoint of ensuring high speed ink absorption inan ink jet printer, the ratio by weight is more preferably 2/1 or more.

For example, when a coating solution obtained by thoroughly dispersinggas phase process silica fine particles having an average primaryparticle size of 20 nm or less and a water-soluble resin in an aqueoussolution in a ratio by weight (x/y) of from 2/1 to 5/1 is coated on asupport and the coated layer is dried, a three dimensional networkstructure is formed with the secondary particles of the silica fineparticles as the network chains, and a transparent porous film having anaverage pore diameter of 30 nm or less, a void ratio of from 50 to 80%,a specific pore volume of 0.5 ml/g or more, and a specific surface areaof 100 m²/g or more can be easily formed.

Crosslinking Agent:

The coloring material-receiving layer of a sheet for ink jet recordingin the present invention is a coating layer containing fine particles, awater-soluble resin and a crosslinking agent capable of crosslinking thewater-soluble resin, and the coloring material-receiving layer ispreferably a porous layer formed by curing by a crosslinking reaction ofthe crosslinking agent and the water-soluble resin.

Boron compounds are preferably used for crosslinking the abovewater-soluble resins, in particular, polyvinyl alcohol. As the boroncompounds, e.g., borax, boric acid, borate (e.g., orthoborate, InBO₃,ScBO₃, YBO₃, LaBO₃, Mg₃(BO₃)₂, CO₃(BO₃)₂), diborate (e.g., Mg₂B₂O₅,CO₂B₂O₅), metaborate (e.g., LiBO₂, Ca(BO₂)₂, NaBO₂, KBO₂), tetraborate(e.g., Na₂B₄O₇·10H₂O), and pentaborate (e.g., KB₅O₈·4H₂O, Ca₂B₆O₁₁.7H₂O,CsB₅O₅) can be exemplified. Borax, boric acid and borate are preferredamong these boron compounds in the point of capable of quickly bringingabout crosslinking reaction, and boric acid is especially preferred.

Besides the boron compounds, the following compounds can also be used asthe crosslinking agents of the water-soluble resins.

The examples of the compounds include aldehyde compounds, e.g.,formaldehyde, glyoxal and glutaraldehyde; ketone compounds, e.g.,diacetyl and cyclopentanedione; active halogen compounds, e.g.,bis(2-chloroethylurea)-2-hydroxy-4,6-dichloro-1,3,5-triazin e and2,4-dichloro-6-s-triazine sodium salt; active vinyl compounds, e.g.,divinyl sulfonic acid, 1,3-vinylsulfonyl-2-propanol,N,N′-ethylene-bis(vinylsulfonylacetamide), and1,3,5-triacryloyl-hexahydro-s-triazine; N-methylol compounds, e.g.,dimethylolurea and methyloldimethylhydantoin; melamine resins, e.g.,methylolmelamine and alkylated methylolmelamine; epoxy resins;isocyanate compounds, e.g., 1,6-hexamethylenediisocyanate; aziridinecompounds disclosed in U.S. Pat. Nos. 3,017,280 and 2,983,611;carboxyimide compounds disclosed in U.S. Pat. No. 3,100,704; epoxycompounds, e.g., glycerol triglycidyl ether; ethyleneimino compounds,e.g., 1,6-hexamethylene-N,N′-bis-ethyleneurea; halogenatedcarboxyaldehyde compounds, e.g., mucochloric acid and mucophenoxychloricacid; dioxane compounds, e.g., 2,3-dihydroxydioxane; metal-containingcompounds, e.g., titanium lactate, aluminum sulfate, chromium alum,potassium alum, zirconyl acetate and chromiumacetate; polyaminecompounds, e.g., tetraethylenepentamine; hydrazide compounds, e.g.,adipic dihydrazide; and low molecular weight compounds and polymershaving 2 or more oxazoline groups.

These crosslinking agents may be used alone or in combination of two ormore.

Taking a boron compound as an example, crosslinking is preferablyperformed as follows. That is, the coloring material-receiving layer isa layer obtained by crosslinking a coated layer coated with a coatingsolution containing fine particles, a water-soluble resin containingpolyvinyl alcohol and a boron compound (hereinafter the coating solutionis sometimes referred to as the first coating solution), and thecrosslinking is performed by applying a basic solution having a pH valueof 8 or more (hereinafter the coating solution is sometimes referred toas the second coating solution) to the coated layer or film (1)simultaneously with the coating of the above coating solution, or (2) inthe middle of drying of the coated layer formed by coating the coatingsolution and before the coated layer shows falling-rate-drying.

The use amount of the crosslinking agents is preferably from 1 to 50 wt%, and more preferably from 5 to 40 wt %, based on the water-solubleresin.

Mordant:

In the present invention, a mordant is added to a coloringmaterial-receiving layer for the purpose of improving the waterproofnessand blotting with aging of the image formed.

As such mordants, cationic polymers (cationic mordants) as organicmordants and inorganic mordants are preferably used. By adding themordant to a coloring material-receiving layer, an interaction isbrought about between the mordant and a liquid ink containing an anionicdye as the coloring material, to thereby stabilize the coloringmaterial, thus, waterproofness and blotting with aging can be improved.Organic mordants and inorganic mordants may be used alone, or organicmordants and inorganic mordants may be used in combination.

A mordant may be added to a coating solution containing fine particlesand a water-soluble resin (the first coating solution), or may be addedto the second coating solution and coated in the case where there is afear of generating aggregation between the mordant and the fineparticles.

As the cationic mordants, polymer mordants having a primary, secondaryor tertiary amino group, or a quaternary ammonium salt group as thecationic group are preferably used, but cationic non-polymer mordantscan also be used.

As the polymer mordants, homopolymers of monomers (mordant monomers)having a primary, secondary or tertiary amino group and the saltthereof, or a quaternary ammonium salt group, copolymers or condensationpolymers of these mordant monomers with other monomers (hereinafterreferred to as “non-mordant monomers”) are preferably used. Thesepolymer mordants can be used in the form of water-soluble polymers orwater-dispersible latex particles.

The examples of the above monomers (mordant monomers) include, e.g.,trimethyl-p-vinylbenzylammonium chloride,trimethyl-m-vinylbenzylammonium chloride,triethyl-p-vinyl-benzylammonium chloride, triethyl-m-vinylbenzylammoniumchloride, N,N-dimethyl-N-ethyl-N-p-vinylbenzylammonium chloride,N,N-diethyl-N-methyl-N-p-vinylbenzylammonium chloride,N,N-dimethyl-N-n-propyl-N-p-vinylbenzylammonium chloride,N,N-dimethyl-N-n-octyl-N-p-vinylbenzylammonium chloride,N,N-dimethyl-N-benzyl-N-p-vinylbenzylammonium chloride,N,N-diethyl-N-benzyl-N-p-vinylbenzylammonium chloride,N,N-dimethyl-N-(4-methyl)benzyl-N-p-vinylbenzyl-ammonium chloride,N,N-dimethyl-N-phenyl-N-p-vinylbenzyl-ammonium chloride;trimethyl-p-vinylbenzylammonium bromide, trimethyl-m-vinylbenzylammoniumbromide, trimethyl-p-vinylbenzylammonium sulfonate,trimethyl-m-vinylbenzylammonium sulfonate,trimethyl-p-vinylbenzylammonium acetate,trimethyl-m-vinyl-benzylammonium acetate,N,N,N-triethyl-N-2-(4-vinylphenyl)-ethylammonium chloride,N,N,N-triethyl-N-2-(3-vinylphenyl)-ethylammonium chloride,N,N-diethyl-N-methyl-N-2-(4-vinyl-phenyl)ethylammonium chloride,N,N-diethyl-N-methyl-N-2-(4-vinylphenyl)ethylammonium acetate;quaternary products of N,N-dimethylaminoethyl (meth) acrylate,N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl(meth)acrylate, N,N-diethylaminopropyl (meth)acrylate,N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl(meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, andN,N-diethylaminopropyl (meth)acrylamide by methyl chloride, ethylchloride, methyl bromide, ethyl bromide, methyl iodide or ethyl iodide,and sulfonates, alkylsulfonates, acetates and alkylcarboxylates of thesemonomers obtained by substituting the anions of them.

The examples of mordant monomers further includemonomethyldiallylammonium chloride,trimethyl-2-(methacryloyloxy)ethylammonium chloride,triethyl-2-(methacryloyloxy)ethylammonium chloride,trimethyl-2-(acryloyloxy)ethylammonium chloride,triethyl-2-(acryloyloxy)ethylammonium chloride,trimethyl-3-(methacryloyloxy)propylammonium chloride,triethyl-3-(methacryloyloxy)propylammonium chloride,trimethyl-2-(methacryloylamino)ethylammonium chloride,triethyl-2-(methacryloylamino)ethylammonium chloride,trimethyl-2-(acryloylamino)ethylammonium chloride,triethyl-2-(acryloylamino)ethylammonium chloride,trimethyl-3-(methacryloylamino)propylammonium chloride,triethyl-3-(methacryloylamino)propylammonium chloride,trimethyl-3-(acryloylamino)propylammonium chloride,triethyl-3-(acryloylamino)propylammonium chloride;N,N-dimethyl-N-ethyl-2-(methacryloyloxy)ethylammonium chloride,N,N-diethyl-N-methyl-2-(methacryloyloxy)ethyl-ammonium chloride,N,N-dimethyl-N-ethyl-3-(acryloylamino)-propylammonium chloride,trimethyl-2-(methacryloyloxy)ethylammonium bromide,trimethyl-3-(acryloylamino)propylammonium bromide,trimethyl-2-(methacryloyloxy)ethylammonium sulfonate andtrimethyl-3-(acryloylamino)propylammonium acetate.

As other copolymerizable monomers, N-vinylimidazole andN-vinyl-2-methylimidazole can also be exemplified.

Allylamine, diallylamine, and the derivatives and salts of allylamineand diallylamine can also be used. The examples of these compoundsinclude allylamine, allylamine hydrochloride, allylamine acetate,allylamine sulfate, diallylamine, diallylamine hydrochloride,diallylamine acetate, diallylamine sulfate, diallylmethylamine and thesalts of diallylmethylamine (as the salts, e.g., hydrochloride, acetateand sulfate), diallylethylamine and the salts of diallylethylamine (asthe salts, e.g., hydrochloride, acetate and sulfate), anddiallyldimethylammonium salt (as the counter anions of the salt,chloride, acetate ion and sulfate ion are exemplified). Since allylaminederivatives and diallylamine derivatives are poor in polymerizability inthe form of amine, they are generally polymerized in the form of salt,and desalted, if necessary.

It is also possible to perform polymerization by using N-vinylacetamideor N-vinylformamide as a unit, and to make a vinylamine unit byhydrolysis after polymerization, and compounds having this vinylamineunit as a salt can also be used.

The above non-mordant monomers are monomers not containing a basic groupor a cationic group, such as a primary, secondary or tertiary aminogroup and the salt thereof, or a quaternary ammonium salt group, and notshowing or showing substantially a little interaction with the dyes inink jet ink.

The examples of non-mordant monomers include, e.g., alkyl(meth)acrylate; cycloalkyl (meth)acrylate, e.g., cyclohexyl(meth)acrylate; aryl (meth)acrylate, e.g., phenyl (meth)acrylate;aralkyl ester, e.g., benzyl (meth)acrylate; aromatic vinyls, e.g.,styrene, vinyltoluene and a-methyl-styrene; vinyl esters, e.g., vinylacetate, vinyl propionate, and vinyl bersatite; allyl esters, e.g.,allyl acetate; halogen-containing monomers, e.g., vinylidene chlorideand vinyl chloride; vinyl cyanide, e.g., (meth)acrylonitrile; andolefins, e.g., ethylene and propylene.

As the alkyl (meth)acrylate, alkyl (meth)acrylate in which the alkylmoiety has from 1 to 18 carbon atoms is preferred, e.g., methyl(meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl(meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl(meth)-acrylate, hexyl (meth)acrylate, octyl (meth)acrylate,2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and stearyl(meth)acrylate are exemplified.

Methyl acrylate, ethyl acrylate, methyl methacrylate, ethylmethacrylate, and hydroxyethyl methacrylate are especially preferred.

These non-mordant monomers may also be used alone or in combination oftwo or more.

As the polymer mordants, the following polymers can also be preferablyused, e.g., polydiallyldimethylammonium chloride,polymethacryloyloxyethyl-β-hydroxyethyldimethyl-ammonium chloride,polyethyleneimine, polyallylamine and derivatives thereof,polyamide-polyamine resins, cationic starch, dicyandiamide-formalincondensation products, dimethyl-2-hydroxypropylammonium salt polymers,polyamidine, polyvinylamine, dicyan series cationic resins representedby dicyandiamide-formalin condensation products, polyamine seriescationic resins represented by dicyanamide-diethylene-triaminepolycondensation products, epichlorohydrin-dimethylamine additionpolymers, dimethyldialinammonium chloride-SO₂ copolymers, diallylaminesalt-SO₂ copolymers, (meth) acrylate-containing polymers having aquaternary ammonium salt group-substituted alkyl group at the estermoiety, and styryl type polymers having a quaternary ammonium saltgroup-substituted alkyl group.

The polymer mordants are specifically disclosed in JP-A-48-28325,JP-A-54-74430, JP-A-54-124726, JP-A-55-22766, JP-A-55-142339,JP-A-60-23850, JP-A-60-23851, JP-A-60-23852, JP-A-60-23853,JP-A-60-57836, JP-A-60-60643, JP-A-60-118834, JP-A-60-122940,JP-A-60-122941, JP-A-60-122942, JP-A-60-235134, JP-A-1-161236, U.S. Pat.Nos. 2,484,430, 2,548,564, 3,148,061, 3,309,690, 4,115,124, 4,124,386,4,193,800, 4,273,853, 4,282,305, 4,450,224, JP-A-1-161236,JP-A-10-81064, JP-A-10-119423, JP-A-10-157277, JP-A-10-217601,JP-A-11-348409, JP-A-2001-138621, JP-A-2000-43401, JP-A-2000-211235,JP-A-2000-309157, JP-A-2001-96897, JP-A-2001-138627, JP-A-11-91242,JP-A-8-2087, JP-A-8-2090, JP-A-8-2091, JP-A-8-2093, JP-A-8-174992,JP-A-11-192777, JP-A-2001-301314, JP-B-5-35162, JP-B-5-35163,JP-B-5-35164, JP-B-5-88846, JP-A-7-118333, JP-A-2000-344990, JapanesePatent Nos. 2648847 and 2661677. Polyallylamine and polyallylaminederivatives are particularly preferred.

As the organic mordants for use in the present invention, polyallylamineand polyallylamine derivatives having a weight average molecular weightof 100,000 or less are preferred.

However, in the present invention, mordants containing 1% or less of alow molecular weight component having a molecular weight 500 or less areused. The molecular weight can be determined by gel permeationchromatography (GPC).

As the polyallylamine and polyallylamine derivatives, well-known variousallylamine polymers and derivatives thereof can be used in the presentinvention. The examples of such derivatives include salts ofpolyallylamine and acids (the acids include inorganic acids, e.g.,hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid,organic acids, e.g., methanesulfonic acid, toluenesulfonic acid, aceticacid, propionic acid, cinnamic acid, and (meth)acrylic acid,combinations of these acids, and allylamine only a part of which is madesalt), derivatives obtained by a high polymer reaction ofpolyallylamine, and copolymers of polyallylamine and othercopolymerizable monomers (the specific examples of the monomers include(meth)acrylic esters, styrenes, (meth)acrylamides, acrylonitrile andvinyl esters).

The specific examples of polyallylamines and polyallylamines derivativesare disclosed in JP-B-62-31722, JP-B-2-14364, JP-B-63-43402,JP-B-63-43403, JP-B-63-45721, JP-B-63-29881, JP-B-1-26362, JP-B-2-56365,JP-B-2-57084, JP-B-4-41686, JP-B-6-2780, JP-B-6-45649, JP-B-6-15592,JP-B-4-68622, Japanese Patent Nos. 3199227, 3008369, JP-A-10-330427,JP-A-11-21321, JP-A-2000-281728, JP-A-2001-106736, JP-A-62-256801,JP-A-7-173286, JP-A-7-213897, JP-A-9-235318, JP-A-9-302026,JP-A-11-21321, WO 99/21901, WO 99/19372, JP-A-5-140213, andJP-T-11-506488 (the term “JP-T” as used herein means a publishedJapanese translation of a PCT patent application).

As the mordants for use in the present invention, inorganic mordants canalso be used, e.g., polyvalent water-soluble metal salts and hydrophobicmetal salt compounds are exemplified.

The specific examples of inorganic mordants include, e.g., salts andcomplexes of metals selected from magnesium, aluminum, calcium,scandium, titanium, vanadium, manganese, iron, nickel, copper, zinc,gallium, germanium, strontium, yttrium, zirconium, molybdenum, indium,barium, lanthanum, cerium, praseodymium, neodymium, samarium, europium,gadolinium, dysprosium, erbium, ytterbium, hafnium, tungsten and bismuthare exemplified.

Specifically, the examples of inorganic mordants include, e.g., calciumacetate, calcium chloride, calcium formate, calcium sulfate, bariumacetate, barium sulfate, barium phosphate, manganese chloride, manganeseacetate, manganese formate dihydrate, ammonium manganese sulfatehexahydrate, cupric chloride, copper (II) ammonium chloride dihydrate,copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate,nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetatetetrahydrate, ammonium nickel sulfate hexahydrate, nickel amidosulfatetetrahydrate, aluminum sulfate, aluminum alum, basic aluminumpolyhydroxide, aluminum sulfite, aluminum thiosulfate, aluminumpolychloride, aluminum nitrate nonahydrate, aluminum chloridehexahydrate, ferrous bromide, ferrous chloride, ferric chloride, ferroussulfate, ferric sulfate, zinc phenolsulfonate, zinc bromide, zincchloride, zinc nitrate hexahydrate, zinc sulfate, titaniumtetrachloride, tetraisopropyl titanate, titanium acetylacetonate,titanium lactate, zirconium acetylacetonate, zirconyl acetate, zirconylsulfate, ammonium zirconium carbonate, zirconyl stearate, zirconyloctylate, zirconyl nitrate, zirconium oxychloride, zirconiumhydroxychloride, chromium acetate, chromium sulfate, magnesium sulfate,magnesium chloride hexahydrate, magnesium citrate nonahydrate, sodiumphosphotungstate, tungsten sodium citrate, dodecatungstophosphaten-hydrate, dodecatungstosilicate hexacosahydrate, molybdenum chloride,dodecamolybdophosphate n-hydrate, gallium nitrate, germanium nitrate,strontium nitrate, yttrium acetate, yttrium chloride, yttrium nitrate,indium nitrate, lanthanum nitrate, lanthanum chloride, lanthanumacetate, lanthanum benzoate, cerium chloride, cerium sulfate, ceriumoctylate, praseodymium nitrate, neodymium nitrate, samarium nitrate,europium nitrate, gadolinium nitrate, dysprosium nitrate, erbiumnitrate, ytterbium nitrate, hafnium chloride and bismuth nitrate.

As the inorganic mordants for use in the present invention,aluminum-containing compounds, titanium-containing compounds,zirconium-containing compounds, and metallic compounds belonging togroup IIIB of the Periodic Table (salts or complexes) are preferablyused.

The amount of mordants contained in a coloring material-receiving layerin the invention is preferably from 0.01 to 5 g/m², and more preferablyfrom 0.1 to 3 g/m².

Other Components:

A sheet for ink jet recording for use in the present invention canfurther contain various well-known additives according to necessity,e.g., acids, ultraviolet absorbers, antioxidants, fluorescentbrightening agents, monomers, polymerization initiators, polymerizationinhibitors, blotting preventives, antiseptics, viscosity stabilizers,defoaming agents, surfactants, antistatic agents, matting agents, curlpreventing agents and waterproofing agents, can be used.

In the present invention, a coloring material-receiving layer maycontain acids. The surface pH value of a coloring material-receivinglayer is adjusted to 3 to 8, preferably from 5 to 7.5 by adding acids.The yellowing resistance of the white area of sheet is improved by theaddition of acids. The surface pH value is measured according to MethodA (a coating method) of surface pH measurements established by J. TAPPI.For example, the measurement can be performed with a pH measuring setfor paper surface “Model MPC” (manufactured by KYORITSU CHEMICAL-CHECKLab., Corp.) corresponding to Method A.

The specific examples of the acids include formic acid, acetic acid,glycolic acid, oxalic acid, propionic acid, malonic acid, succinic acid,adipic acid, maleic acid, malic acid, tartaric acid, citric acid,benzoic acid, phthalic acid, isophthalic acid, glutaric acid, gluconicacid, lactic acid, aspartic acid, glutamic acid, salicylic acid,salicylic acid metal salt (salts of Zn, Al, Ca, Mg), methanesulfonicacid, itaconic acid, benzenesulfonic acid, toluenesulfonic acid,trifluoromethanesulfonic acid, styrenesulfonic acid, trifluoroaceticacid, barbituric acid, acrylic acid, methacrylic acid, cinnamic acid,4-hydroxybenzoic acid, aminobenzoic acid, naphthalenedisulfonic acid,hydroxybenzenesulfonic acid, toluenesulfinic acid, benzene-sulfinicacid, sulfanilic acid, sulfamic acid, α-resorcylic acid, β-resorcylicacid, γ-resorcylic acid, gallic acid, phloroglycine, sulfosalicylicacid, ascorbic acid, erythorbic acid, bisphenolic acid, hydrochloricacid, nitric acid, sulfuric acid, phosphoric acid, polyphosphoric acid,boric acid and boronic acid. These acids are added so that the pH of thesurface of a coloring material-receiving layer reaches from 3 to 8.

These acids may be used in the form of metal salts (e.g., salts ofsodium, potassium calcium, cesium, zinc, copper, iron, aluminum,zirconium, lanthanum, yttrium, magnesium, strontium, cerium), or aminesalts (e.g., ammonia, triethylamine, tributylamine, piperazine,2-methylpiperazine, and polyallylamine).

In the present invention, it is preferred for a coloringmaterial-receiving layer to contain storing property improvers, e.g.,ultraviolet absorbers, antioxidants and blotting preventives.

As these ultraviolet absorbers, antioxidants and blotting preventives,alkylated phenol compounds (including hindered phenol compounds),alkylthiomethylphenol compounds, hydroquinone compounds, alkylatedhydroquinone compounds, tocopherol compounds, thiodiphenyl ethercompounds, compounds having 2 or more thioether bonds, bisphenolcompounds, O—, N- and S-benzyl compounds, hydroxybenzyl compounds,triazine compounds, phosphonate compounds, acylaminophenol compounds,ester compounds, amide compounds, ascorbic acid, amine seriesantioxidants, 2-(2-hydroxyphenyl)benzotriazole compounds,2-hydroxybenzophenone compounds, acrylate, water-soluble or hydrophobicmetal salts, organic metal compounds, metal complexes, hindered aminecompounds (including TEMPO compounds),2-(2-hydroxyphenyl)-1,3,5-triazine compounds, metal deactivators,phosphite compounds, phosphonate compounds, hydroxylamine compounds,nitron compounds, peroxide scavengers, polyamide stabilizers, polyethercompounds, basic auxiliary stabilizers, nucleus agents, benzofuranoncompounds, indolinone compounds, phosphine compounds, polyaminecompounds, thiourea compounds, urea compounds, hydrazide compounds,amidine compounds, sugar compounds, hydroxybenzoic acid compounds,dihydroxybenzoic acid compounds, and trihydroxybenzoic acid compoundsare exemplified.

Of these compounds, alkylated phenol compounds, compounds having 2 ormore thioether bonds, bisphenol compounds, ascorbic acid, amine seriesantioxidants, water-soluble or hydrophobic metal salts, organic metalcompounds, metal complexes, hindered amine compounds, hydroxylaminecompounds, polyamine compounds, thiourea compounds, hydrazide compounds,hydroxybenzoic acid compounds, dihydroxybenzoic acid compounds, andtrihydroxybenzoic acid compounds are preferred.

The specific examples of the compounds are disclosed in the followingpatents: Japanese Patent Application No. 2002-13005, JP-A-10-182621,JP-A-2001-260519, JP-B-4-34953, JP-B-4-34513, JP-A-11-170686,JP-B-4-34512, EP 1138509, JP-A-60-67190, JP-A-7-276808, JP-A-2001-94829,JP-A-47-10537, JP-A-58-111942, JP-A-58-212844, JP-A-59-19945,JP-A-59-46646, JP-A-59-109055, JP-A-63-53544, JP-B-36-10466,JP-B-42-26187, JP-B-48-30492, JP-B-48-31255, JP-B-48-41572,JP-B-48-54965, JP-B-50-10726, U.S. Pat. Nos. 2,719,086, 3,707,375,3,754,919, 4,220,711, JP-B-45-4699, JP-B-54-5324, EP 223739, EP 309401,EP 309402, EP 310551, EP 310552, EP 459416, German Patent 3,435,443,JP-A-54-48535, JP-A-60-107384, JP-A-60-107383, JP-A-60-125470,JP-A-60-125471, JP-A-60-125472, JP-A-60-287485, JP-A-60-287486,JP-A-60-287487, JP-A-60-287488, JP-A-61-160287, JP-A-61-185483,JP-A-61-211079, JP-A-62-146678, JP-A-62-146680, JP-A-62-146679,JP-A-62-282885, JP-A-62-262047, JP-A-63-051174, JP-A-63-89877,JP-A-63-88380, JP-A-66-88381, JP-A-63-113536, JP-A-63-163351,JP-A-63-203372, JP-A-63-224989, JP-A-63-251282, JP-A-63-267594,JP-A-63-182484, JP-A-1-239282, JP-A-2-262654, JP-A-2-71262,JP-A-3-121449, JP-A-4-291685, JP-A-4-291684, JP-A-5-61166,JP-A-5-119449, JP-A-5-188687, JP-A-5-188686, JP-A-5-110490,JP-A-5-1108437, JP-A-5-170361, JP-B-48-43295, JP-B-48-33212, U.S. Pat.Nos. 4,814,262 and 4,980,275.

Each of the additives described above as other components may be usedalone or in combination of two or more. These other components are usedin the form of solution in water, dispersion, polymer dispersion,emulsion, oil droplets, or microencapsulation. The addition amount ofother components to an ink jet recording sheet is preferably from 0.01to 10 g/m².

For the purpose of improving the dispersibility of inorganic fineparticles, the inorganic fine particles may be subjected tosurface-covering treatment with a silane coupling agent. It is preferredthat the silane coupling agent have an organic functional group (e.g., avinyl group, an amino group (a primary, secondary or tertiary aminogroup, a quaternary ammonium salt group), an epoxy group, a mercaptogroup, a chloro group, an alkyl group, a phenyl group or an ester group)besides the part for coupling treatment.

In the present invention, it is preferred for the coating solution for acoloring material-receiving layer to contain a surfactant. As thesurfactant, any of cationic, anionic, nonionic, ampholytic, fluorine andsilicone surfactants can be used.

The examples of the nonionic surfactants include polyoxyalkylene alkylethers and polyoxyalkylene alkylphenyl ethers (e.g., diethylene glycolmonoethyl ether, diethylene glycol diethyl ether, polyoxyethyene laurylether, polyoxyethyene stearyl ether and polyoxyethylene nonylphenylether), oxyethylene-oxypropylene block copolymer, sorbitan fatty acidesters (e.g., sorbitan monolaurate, sorbitan monooleate and sorbitantrioleate), polyoxyethylene sorbitan fatty acid esters (e.g.,polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitanmonooleate and polyoxyethylene sorbitan trioleate), polyoxyethylenesorbitol fatty acid esters (e.g., polyoxyethylene sorbitol tetraoleate),glycerol fatty acid esters (e.g., glycerol monooleate), polyoxyethyleneglycerol fatty acid esters (e.g., polyoxyethylene glycerol monostearateand polyoxyethylene glycerol monooleate), polyoxyethylene fatty acidesters (e.g., polyethylene glycol monolaurate and polyethylene glycolmonooleate), polyoxyethylene alkylamine, acetylene glycols (e.g.,2,4,7,9-tetramethyl-5-decine-4,7-diol, and ethylene oxide adducts of thediol, propylene oxide adducts), and polyoxyalkylene alkyl ethers arepreferably used. The nonionic surfactants can be used in the firstcoating solution and the second coating solution. Further, the nonionicsurfactants may be used alone or two or more of them may be used incombination.

The examples of the ampholytic surfactants include amino acid type,carboxyammonium betaine type, sulfonammonium betaine type, ammoniumsulfate betaine type and imidazolium betaine type surfactants, and thecompounds disclosed, e.g., in U.S. Pat. No. 3,843,368, JP-A-59-49535,JP-A-63-236546, JP-A-5-303205, JP-A-8-262742, JP-A-10-282619, JapanesePatent Nos. 2514194, 2759795, and JP-A-2000-351269 can be preferablyused. Of the above ampholytic surfactants, amino acid type,carboxyammonium betaine type and sulfonammonium betaine type surfactantsare preferred. The ampholytic surfactants may be used alone or two ormore of them may be used in combination.

The examples of the anionic surfactants include fatty acid salts (e.g.,sodium stearate and potassium oleate), alkyl sulfates (e.g., sodiumlauryl sulfate and triethanolamine lauryl sulfate), sulfonates (e.g.,sodium dodecylbenzenesulfonate), alkyl sulfosuccinate (e.g., sodiumdioctyl sulfosuccinate), alkyldiphenyl ether disulfonate and alkylphosphate.

The examples of the cationic surfactants include alkylamine salts,quaternary ammonium salts, pyridinium salts and imidazolium salts.

The examples of the fluorine surfactants include compounds derivedthrough intermediates having a perfluoroalkyl group by the method ofelectrolytic fluorination, telomerization or oligomerization.

For example, perfluoroalkyl sulfonate, perfluoroalkyl carboxylate,perfluoroalkyl ethylene oxide adducts, perfluoroalkyl trialkylammoniumsalt, perfluoroalkyl group-containing oligomers, and perfluoroalkylphosphate are exemplified as the fluorine surfactants.

As the silicone surfactants, silicone oils modified with an organicgroup are preferred, and they can take the structure in which the sidechain of the siloxane structure is modified with an organic group, thestructure in which both terminals are modified, and the structure inwhich one terminal is modified. As the examples of modifications by anorganic group, amino modification, polyether modification, epoxymodification, carboxyl modification, carbinol modification, alkylmodification, aralkyl modification, phenol modification, and fluorinemodification are exemplified.

The amount of surfactants used in the invention is preferably from 0.001to 2.0% of the coating solution for a coloring material-receiving layer,and more preferably from 0.01 to 1.0%. When two or more coatingsolutions are used for forming a coloring material-receiving layer, asurfactant is preferably added to each layer.

In the present invention, it is preferred that a coloringmaterial-receiving layer contain a high boiling point organic solventfor preventing curling. The high boiling point organic solvent is anorganic compound having a boiling point of 150° C. or higher at normalpressure, and a water-soluble or hydrophobic compound. The high boilingpoint organic solvent may be liquid or solid state at room temperature,and they may be a high molecular weight compound or low molecular weightcompound.

The specific examples of the high boiling point organic solvents includearomatic carboxylic esters (e.g., dibutyl phthalate, diphenyl phthalateand phenyl benzoate), aliphatic carboxylic esters (e.g., dioctyladipate, dibutyl sebacate, methyl stearate, dibutylmaleate, dibutylfumarate, and triethyl acetylcitrate), phosphoric esters (e.g., trioctylphosphate and tricresyl phosphate), epoxys (e.g., epoxidized soybeanoil, epoxidized fatty acid methyl), alcohols (e.g., stearyl alcohol,ethylene glycol, propylene glycol, diethylene glycol, triethyleneglycol, glycerol, diethylene glycol monobutyl ether (DEGMBE),triethylene glycol monobutyl ether, glycerol monomethyl ether,1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol,1,2,6-hexanetriol, thioglycerol, triethanolamine, andpolyethyleneglycol), vegetable oils (e.g., soybean oil and sunfloweroil), and higher aliphatic carboxylic acid (e.g., linoleic acid andoleic acid).

Support:

As the supports for an ink jet recording sheet in the invention, bothtransparent supports comprising transparent materials such as plasticsand opaque supports comprising opaque materials such as paper can beused. For making the best use of transparency of a coloringmaterial-receiving layer, it is preferred to use transparent supports orhighly glossy opaque supports.

As the materials which can be used for the transparent supports,materials which are transparent and have properties capable of resistingradiant heat when used in HOP or backlight display are preferably used.Specifically, polyesters, e.g., polyethylene terephthalate (PET);polysulfone, polyphenylene oxide, polyimide, polycarbonate and polyamideare exemplified as such materials. Polyesters are preferred of thesematerials, and polyethylene terephthalate is especially preferred.

The thickness of the transparent support is not particularly restricted,but a thickness of from 50 to 200 μm is preferred from easy handling.

It is preferred for a highly glossy opaque support to have glossiness ofthe surface, on which a coloring material-receiving layer is provided,of 40% or higher. The glossiness is a value obtained by the measurementaccording to the method described in JIS P-8142 (the test method of 75°specular glossiness of paper and cardboard). Specifically, the followingsupport are exemplified.

As such supports, highly glossy paper supports, e.g., art paper, coatedpaper, cast coated paper, and baryta paper used for a silver saltphotographic support; polyesters, e.g., polyethylene terephthalate(PET); cellulose esters, e.g., nitrocellulose, cellulose acetate, andcellulose acetate butyrate; highly glossy films obtained by adding awhite pigment to plastic films to make opaque (surfaces may be subjectedto calendering treatment), e.g., polysulfone, polyphenylene oxide,polyimide, polycarbonate, and polyamide; and supports obtained byproviding a polyolefin coating layer containing or not containing awhite pigment on the surface of each of the above various papersupports, the transparent supports or highly glossy films containing awhite pigment are exemplified.

White pigment-containing expanded polyester films (e.g., expanded PETformed by adding polyolefin fine particles and stretching to therebyform voids) can also be preferably used. Resin-coated paper for use inphotographic paper for silver salt photography) can also be preferablyused.

The thickness of the opaque support is not also particularly restricted,but a thickness of from 50 to 300 μm is preferred from easy handling.

The surfaces of the above supports may be subjected to corona dischargetreatment, glow discharge treatment, flame treatment or ultravioletirradiation treatment for improving wettability and adhesion.

Base paper for use in the above resin-coated paper is described indetail below.

The base paper comprises woodpulp as the main component, and paper ismanufactured by using synthetic pulp, e.g., polypropylene, or syntheticfibers, e.g., nylon and polyester, in addition to the woodpulp, ifnecessary. As the above woodpulp, any of LBKP, LBSP, NBKP, NBSP, LDP,NDP, LUKP and NUKP can be used, but it is preferred that LBKP, NBSP,LBSP, NDP and LDP in which short fibers predominate be used in a greateramount.

However, the ratio of LBSP and/or LDP is preferably from 10 to 70 wt %.

As the synthetic pulp, chemical pulp containing less impurities (e.g.,sulfate pulp and sulfite pulp) is preferably used, and pulp subjected tobleaching treatment to improve brightness is also useful.

Base paper can arbitrarily contain sizes, e.g., higher fatty acid andalkyl ketene dimer, white pigments, e.g., calcium carbonate, talc andtitanium oxide, paper strength intensifiers, e.g., starch,polyacrylamide and polyvinyl alcohol, fluorescent brightening agents,moisture content-retaining agents, e.g., polyethylene glycol,dispersants, and softening agents, e.g., quaternary ammonium.

The freeness of the pulp for use in paper-making is preferably from 200to 500 ml according to the regulation by CSF, and the fiber length afterbeating in the sum of wt % of 24 mesh residue and wt % of 42 meshresidue is preferably from 30 to 70 wt % according to the regulation byJIS P-8207. The wt % of 4 mesh residue is preferably 20 wt % or less.

Weighing of base paper is preferably from 30 to 250 g, and particularlypreferably from 50 to 200 g. The thickness of base paper is preferablyfrom 40 to 250 μm. Base paper can be subjected to calendering treatmentduring or after paper-making to give the base paper high smoothness. Thebulk density of base paper is generally from 0.7 to 1.2 g/m² (JISP-8118).

The stiffness of base paper is preferably from 20 to 200 g on thecondition regulated by JIS P-8143.

Surface sizes may be coated on the surface of base paper and the samesurface sizes that can be added to the above base paper can be used.

The pH of base paper is preferably from 5 to 9 when measured by hotwater extraction regulated by JIS P-8113.

Polyethylene to be coated on the front and rear surfaces of base paperis mainly low density polyethylene (LDPE) and/or high densitypolyethylene (HDPE), but LLDPE and polypropylene can also be usedpartially.

As is widely performed in photographic paper, it is preferred thatrutile or anatase type titanium oxide, a fluorescent brightening agentand ultramarine be added to the polyethylene of a polyethylene layerprovided on the side of a support on which a coloring material-receivinglayer is formed for the purpose of improving opacity, brightness andhue. The amount of titanium oxide is generally preferably from 3 to 20wt % of the polyethylene, and more preferably from 4 to 13 wt %. Thethickness of the polyethylene layer is not especially restricted, butthe thickness of both front and rear surface layers is preferably from10 to 50 μm. Further, a subbing layer can be provided on thepolyethylene layer to give the polyethylene layer the adhesionproperties with the coloring material-receiving layer. Water-solublepolyester, gelatin and PVA are preferably used for the subbing layer.The thickness of the subbing layer is preferably from 0.01 to 5 μm.

A polyethylene-coated paper can be used as glossy paper, or can be usedas a matt paper or a silk-finish paper similar to general photographicpaper obtained by embossing when polyethylene is melt-extruded andcoated on the surface of base paper.

A back coat layer can be provided on a support, and white pigments,aqueous binders and other components are exemplified as the componentswhich can be added to the back coat layer.

The examples of the white pigments which are added to the back coatlayer include inorganic white pigments, e.g., precipitated calciumcarbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate,barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinccarbonate, satin white, aluminum silicate, diatomaceous earth, calciumsilicate, magnesium silicate, synthetic amorphous silica, colloidalsilica, colloidal alumina, pseudo-boehmite, aluminum hydroxide, alumina,lithopone, zeolite, hydrated halloysite, magnesium carbonate, andmagnesium hydroxide, and organic white pigments, e.g., styrene seriesplastic pigment, acrylic series plastic pigment, polyethylene,microcapsules, urea resins and melamine resins.

As the aqueous binders used in the back coat layer, water-soluble highpolymers, e.g., styrene-maleate copolymer, styrene-acrylate copolymer,polyvinyl alcohol, silanol-modified polyvinyl alcohol, starch, cationicstarch, casein, gelatin, carboxymethyl cellulose, hydroxyethylcellulose, and polyvinyl pyrrolidone, and water-dispersible highpolymers, e.g., styrene-butadiene latex and acrylic emulsion areexemplified.

As other components which are added to the back coat layer, defoamingagents, foam inhibitors, dyes, fluorescent brightening agents,antiseptics and waterproofing agents are exemplified.

Manufacture of Sheet for Ink Jet Recording:

The coloring material-receiving layer of the sheet for ink jet recordingin the present invention is preferably formed by the method (wet-on-wetcoating method) of coating a first coating solution containing at leastfine particles and a water-soluble resin (hereinafter sometimes referredto as “coating solution (A)”) on the surface of a support, and thencoating a second coating solution containing at least a mordant andhaving a pH value of 8 or more (hereinafter sometimes referred to as“coating solution (B)”) (1) simultaneously with the coating of the firstcoating solution, or (2) in the middle of drying of the coated layerformed by coating of the first coating solution and before the coatedlayer shows falling-rate-drying speed, and curing the coated layercoated with the second coating solution by crosslinking.

Providing a coloring material-receiving layer cured by crosslinking ispreferred from the viewpoint of the improvement of ink absorption andthe prevention of film cracking.

According to the above manufacturing method, since the mordant aboundsin the vicinity of the surface of the coloring material-receiving layer,the coloring material of ink jet is sufficiently mordanted and thewaterproofness of characters and images after printing is improved. Apart of mordant may be contained in coating solution (A), and in such acase the mordants in coating solution (A) and coating solution (B) maybe the same or different.

In the present invention, a coating solution for forming a coloringmaterial-receiving layer containing at least fine particles (e.g., gasphase process silica) and a water-soluble resin (e.g., polyvinylalcohol) (coating solution (A)) can be manufactured, for example, asfollows. That is:

Coating solution (A) can be manufactured by adding gas phase processsilica fine particles and a dispersant to water (e.g., silica fineparticles in water is from 10 to 20 wt %), dispersing the fine particlesand the dispersant with a high speed wet colloid mill (e.g., “Clearmix”manufactured by M Technique Co., Ltd.) at a high speed of 10,000 rpm(preferably from 5,000 to 20,000 rpm) over 20 minutes (preferably from10 to 30 minutes), adding a crosslinking agent (a boron compound) and apolyvinyl alcohol (PVA) aqueous solution (so that, for example, the massof PVA becomes about ⅓ of that of the gas phase process silica fineparticles), and in the case where the betaine surfactant of theinvention is added to the coating solution for a coloringmaterial-receiving layer, the betaine surfactant is added, and thendispersing the mixture on the same rotation condition as above. Theobtained coating solution is in a homogeneous sol state. The coatingsolution is coated on a support according to the following coatingmethod and dried, thus a porous coloring material-receiving layer havinga three dimensional structure can be formed.

Further, water dispersion comprising gas phase process silica and adispersant may be performed by previously preparing a water dispersionsolution of gas phase process silica and adding the water dispersionsolution to an aqueous solution of a dispersant, or an aqueous solutionof a dispersant may be added to a water dispersion solution of gas phaseprocess silica, or they may be mixed simultaneously. Gas phase processsilica of powder may be added to an aqueous solution of a dispersant inplace of a water dispersion solution of gas phase process silica.

After mixing the gas phase process silica and the dispersant, themixture is fined by a disperser, thus a water dispersion solution havingan average particle size of from 50 to 300 nm can be obtained. As thedisperser for obtaining the water dispersion solution, variouswell-known dispersers, e.g., a high speed disperser, a medium-stirringtype disperser (a ball mill and a sand mill), an ultrasonic disperser, acolloid mill disperser, and a high pressure disperser, can be used, butit is preferred to use a stirring type disperser, a colloid milldisperser or a high pressure disperser from the point of effectivelyperforming the dispersion of clumpy fine particles formed.

As the solvents for each process, water, organic solvents and mixedsolvents of them can be used. The examples of organic solvents for usein this coating include alcohols, e.g., methanol, ethanol, n-propanol,i-propanol, and methoxypropanol, ketones, e.g., acetone and methyl ethylketone, tetrahydrofuran, acetonitrile, ethyl acetate and toluene.

Cationic polymers can be used as the above dispersant, and the examplesof mordants described above can be used as cationic polymers. Silanecoupling agents are also preferably used as the dispersant.

The addition amount of the dispersants to fine particles is preferablyfrom 0.1 to 30%, and more preferably from 1 to 10%.

The coating solution for a coloring material-receiving layer can becoated by well-known coating methods, e.g., an extrusion die coater, anair doctor coater, a blade coater, a rod coater, a knife coater, asqueeze coater, a reverse roll coater and a bar coater, can be used.

Simultaneously with or after coating the coating solution for a coloringmaterial-receiving layer (coating solution (A)), coating solution (B) isapplied, but coating solution (B) may be coated before the coated layerbecomes to show falling-rate drying speed. That is, a coloringmaterial-receiving layer is preferably manufactured by introducing amordant into the layer after the coating of the coating solution for thecoloring material-receiving layer (coating solution (A)) while thecoated layer is showing constant-rate drying speed.

The terminology “before the coated layer becomes to show falling-ratedrying speed” generally means a stage of several minutes immediatelyafter coating of the coating solution for a coloring material-receivinglayer, and a phenomenon that the content of the solvent (a dispersionmedium) in a coated layer decreases in proportion to the time, i.e.,“constant-rate drying speed”, is shown during this period. With respectto the time showing “constant-rate drying speed”, Kagaku Kogaku Binran(Chemical Engineering Handbook), pp. 707 to 712, Maruzen Co. (Oct. 25,1980) can be referred to.

As described above, the coated layer is dried after coating the firstcoating solution until the coated layer becomes to show falling-ratedrying speed generally at 50 to 180° C. for 0.5 to 10 minutes, andpreferably from 0.5 to 5 minutes. Drying time of course varies dependingupon the coated amount, but the above range is generally preferred.

As the methods which are applicable before the first coating layer comesto show falling-rate drying speed, (1) a method of further coating, onthe coated layer, coating solution (B), (2) a method of spraying coatingsolution (B), and (3) a method of immersing the support having thecoated layer in coating solution (B) are exemplified.

In the above method (1), coating solution (B) can be coated bywell-known coating methods, e.g., a curtain flow coater, an extrusiondie coater, an air doctor coater, a blade coater, a rod coater, a knifecoater, a squeeze coater, a reverse roll coater and a bar coater, can beused. However, it is preferred to use a method in which a coater doesnot directly come into contact with the already coated first coatinglayer, such as an extrusion die coater, a curtain flow coater, and a barcoater.

After the mordant solution (coating solution (B)) has been coated,drying and curing are performed by heating generally at 40 to 180° C.for 0.5 to 30 minutes, and preferably at 40 to 150° C. for 1 to 20minutes.

Further, when the mordant solution (coating solution (B)) is coatedsimultaneously with the coating of the coating solution for a coloringmaterial-receiving layer (coating solution (A)), a coloringmaterial-receiving layer can be formed by simultaneously coating(multilayer coating) the coating solution for the coloringmaterial-receiving layer (coating solution (A)) and the mordant solution(coating solution (B)) on the support so that the coating solution forthe coloring material-receiving layer (coating solution (A)) comes intocontact with the support, and then drying and curing.

The simultaneous coating (multilayer coating) can be performed by acoating method using, e.g., an extrusion die coater or a curtain flowcoater. After simultaneous coating, the coated layer is dried generallyat 40 to 150° C. for 0.5 to 10 minutes, and preferably at 40 to 100° C.for 0.5 to 5 minutes.

When the simultaneous coating (multilayer coating) is performed with,e.g., an extrusion die coater, two coating solutions discharged at thesame time are multilayer-formed by the discharge port of the extrusiondie coater, i.e., before being coated on the support, and two coatingsolutions are coated on the support in that state. Since the coatingsolutions for two layers multilayered before coating are alreadysusceptible to crosslinking reaction at the interface of two solutionswhen they are transferred to the support, two solutions to be dischargedare liable to be mixed and tackified by the discharge port of theextrusion die coater, and sometimes coating operation is hindered.Accordingly, when simultaneous coating is performed as above, it ispreferred to perform triple layer coating by intervening a barrier layercoating solution (an intermediate layer coating solution) between thecoloring material-receiving layer coating solution (coating solution(A)) and the mordant solution (coating solution (B)).

The barrier layer coating solution can be selected with no limitation.For example, an aqueous solution containing a trace amount ofwater-soluble resin, and water can be used as the barrier layer coatingsolution. The water-soluble resin is used for the purpose of tackifiertaking the coating properties into consideration, and polymers, e.g.,cellulose series resins (e.g., hydroxypropylmethyl cellulose, methylcellulose, and hydroxyethylmethyl cellulose), polyvinyl pyrrolidone andgelatin are exemplified. The mordant may be added to the barrier layer.

After a coloring material-receiving layer is formed on a support,surface smoothness, glossiness, transparency and film strength of thecoloring material-receiving layer can be improved by, e.g., subjectingthe coloring material-receiving layer to calendering treatment by usingcalender and gloss calender and passing through roll nips with heatingunder pressure. However, calendering treatment sometimes causes thereduction of a void ratio (that is, there are cases where ink absorptionlowers), therefore, it is necessary to select conditions bringing aboutless void ratio reduction.

The roll temperature at calendering treatment is preferably from 30 to150° C., and more preferably from 40 to 100° C.

The linear pressure between rolls at calendering treatment is preferablyfrom 50 to 400 kg/cm, and more preferably from 100 to 200 kg/cm.

Since it is necessary for a coloring material-receiving layer to havesufficient absorption capacity capable of absorbing all the droplets inthe case of ink jet recording, the layer thickness has to be decided inrelation to the void ratio in the layer. For example, in the case wherethe ink amount is 8 nL/mm² and the void ratio is 60%, the layerthickness is necessary to be 15 μm or higher.

Considering this point, the layer thickness of a coloringmaterial-receiving layer in the case of ink jet recording is preferablyfrom 10 to 50 μm.

The pore diameter of a coloring material-receiving layer is preferablyfrom 0.005 to 0.030 μm, and more preferably from 0.01 to 0.025 μm, inmedian diameter.

The void ratio and the median diameter of pores can be measured with amercury porosimeter (Pore Sizer-9320-PC2, a trade name, manufactured byShimadzu Corporation).

It is preferred that a coloring material-receiving layer be excellent intransparency. As the criterion of transparency, a haze value of acoloring material-receiving layer formed on a transparent support ispreferably 30% or less, and more preferably 20% or less.

The haze value can be measured with a haze meter (HGM-2DP, manufacturedby Suga Test Instruments Co., Ltd.).

Polymer fine particle dispersion may be added to the constitutionallayer (e.g., a coloring material-receiving layer or a back coat layer)of a sheet for ink jet recording in the present invention. This polymerfine particle dispersion is used for the purpose of improving thephysical properties of films, e.g., dimensional stability, curlingprevention, adhesion prevention, prevention of cracking of films.Polymer fine particle dispersions are disclosed in JP-A-62-245258,JP-A-62-1316648 and JP-A-62-110066. When polymer fine particledispersion having a low glass transition temperature (40° C. or lower)is added to layers containing a mordant, cracking and curling of thelayers can be prevented from occurring. When polymer fine particledispersion having a high glass transition temperature is added to a backcoat layer, curling of the layer can be prevented, also.

A sheet for ink jet recording in the invention can also be manufacturedby the methods disclosed in JP-A-10-81064, JP-A-10-119423,JP-A-10-157277, JP-A-10-217601, JP-A-11-348409, JP-A-2001-138621,JP-A-2000-43401, JP-A-2000-211235, JP-A-2000-309157, JP-A-2001-96897,JP-A-2001-138627, JP-A-11-91242, JP-A-8-2087, JP-A-8-2090, JP-A-8-2091,and JP-A-8-2093.

The ink and ink for ink jet recording, the concentrated ink composition,the method for manufacturing an ink for ink jet recording, and the inkjet recording method of the present invention are described in detailbelow.

As particularly preferred embodiment of the present invention,concentrated ink which is highly concentrated to reduce the volume, inwhich a compound represented by formula (1) is contained to increase theconcentration of the dye and the pigment in the ink, can be exemplified.

When the present invention is applied to concentrated ink, a compoundrepresented by formula (1) is contained in concentrated ink in an amountof from 0.001 to 30 wt %, preferably from 0.01 to 10 wt %, and morepreferably from 0.1 to 5 wt %, to thereby increase the concentration ofa dye and/or a pigment. The concentration of a dye and/or a pigment inconcentrated ink is from 0.01 to 50 wt %, preferably from 0.1 to 20 wt%, and more preferably from 0.5 to 20 wt %.

Even when the concentration of a dye and/or a pigment is high, thestability of ink is maintained with no hindrance in practical use by thepresence of a compound represented by formula (1).

For preparing ink for ink jet recording in usable state fromconcentrated ink, the concentrated ink is diluted so that theconcentration of the dye and/or the pigment becomes the density ofworking state. Water or liquid obtained by excluding the dye, thepigment and one or more other components from the ink composition isused for dilution.

Ink for ink jet recording in the present invention comprises a colorantdissolved in water or an organic solvent, and the colorant is containedin an amount of preferably from 0.2 to 20 wt %, and more preferably from0.5 to 15 wt %. When two kinds of inks having the same hue and differentdye densities, e.g., light cyan ink and cyan ink, are used incombination in an ink set, the dye density by weight of the low densityink to the high density ink is from 1/20 to 1/2, and preferably from1/10 to 3/7.

Ink for use in the present invention comprises a dye or a pigmentdispersed in water or an organic solvent. The ink is preferably awater-soluble ink comprising a water-soluble dye.

One kind or a plurality of dyestuffs are used in ink and an ink set inthe present invention according to the purpose and function of eachconstitutional ink for adjusting the tone of a full color image. Thedyestuffs which can be used are shown below. In the specification of thepresent invention, the terminology “dyestuff” is used in the case whereboth of dye and pigment are meant and the case where it is not necessaryto distinguish dye from pigment.

As the examples of yellow dyestuffs, aryl or heterylazo dyestuffshaving, as the coupling component, e.g., phenols, naphthols, anilines,pyrazolones, pyridones, or open chain type active methylene compounds;azomethine dyestuffs having, as the coupling component, e.g., an openchain type active methylene compound; methine dyestuffs, e.g., abenzylidene dyestuff and a monomethine oxonol dyestuff; and quinonedyestuffs, e.g., a naphthoquinone dyestuff and an anthraquinonedyestuff, are exemplified. Besides these dyestuffs, quinophthalonedyestuffs, nitronitroso dyestuffs, acridine dyestuffs and acridinonedyestuffs can be exemplified. These dyestuffs may be dyestuffs whichdevelop yellow color after a part of the chromophore is dissociated. Insuch a case, the counter cation may be an inorganic cation such asalkali metal and ammonium, may be an organic cation such as pyridiniumand a quaternary ammonium salt, or may be a polymer cation having thesecations as the partial structure.

As the examples of magenta dyestuffs, aryl and heterylazo dyestuffshaving, as the coupling component, e.g., phenols, naphthols or anilines;azomethine dyestuffs having, as the coupling component, e.g.,pyrazolones or pyrazolotriazoles; methine dyestuffs, e.g., an arylidenedyestuff, a styryl dyestuff, a merocyanine dyestuff, and an oxonoldyestuff; carbonium dyestuffs, e.g., a diphenylmethane dyestuff, atriphenylmethane dyestuff and a xanthene dyestuff; quinone dyestuffs,e.g., a naphthoquinone dyestuff, an anthraquinone dyestuff and ananthrapyridone dyestuff; and condensed polycyclic dyestuffs, e.g., adioxazine dyestuff, are exemplified. These dyestuffs may be dyestuffswhich develop magenta color after a part of the chromophore isdissociated. In such a case, the counter cation may be an inorganiccation such as alkali metal and ammonium, may be an organic cation suchas pyridinium and a quaternary ammonium salt, or may be a polymer cationhaving these cations as the partial structure.

As the examples of cyan dyestuffs, azomethine dyestuffs, e.g., anindoaniline dyestuff and an indophenol dyestuff; polymethine dyestuffs,e.g., a cyanine dyestuff, an oxonol dyestuff and a merocyanine dyestuff;carbonium dyestuffs, e.g., a diphenylmethane dyestuff, atriphenylmethane dyestuff and a xanthene dyestuff; phthalocyaninedyestuffs; anthraquinone dyestuffs; aryl and heterylazo dyestuffshaving, as the coupling component, e.g., phenols, naphthols or anilines;and indigo-thioindigo dyestuffs are exemplified. These dyestuffs may bedyestuffs which develop cyan color after a part of the chromophore isdissociated. In such a case, the counter cation may be an inorganiccation such as alkali metal and ammonium, may be an organic cation suchas pyridinium and a quaternary ammonium salt, or may be a polymer cationhaving these cations as the partial structure.

A black dyestuff such as a polyazo dyestuff can also be used.

As water-soluble dyes, direct dyes, acid dyes, food dyes, basic dyes andreactive dyes are exemplified. The preferred examples of these dyes areshown below.

-   C.I. Direct Red 2, 4, 9, 23, 26, 31, 39, 62, 63, 72, 75, 76, 79, 80,    81, 83, 84, 89, 92, 95, 111, 173, 184, 207, 211, 212, 214, 218, 21,    223, 224, 225, 226, 227, 232, 233, 240, 241, 242, 243, 247;-   C.I. Direct Violet 7, 9, 47, 48, 51, 66, 90, 93, 94, 95, 98, 100,    101;-   C.I. Direct Yellow 8, 9, 11, 12, 27, 28, 29, 33, 35, 39, 41, 44, 50,    53, 58, 59, 68, 86, 87, 93, 95, 96, 98, 100, 106, 108, 109, 110,    130, 132, 142, 144, 161, 163;-   C.I. Direct Blue 1, 10, 15, 22, 25, 55, 67, 68, 71, 76, 77, 78, 80,    84, 86, 87, 90, 98, 106, 108, 109, 151, 156, 158, 159, 160, 168,    189, 192, 193, 194, 199, 200, 201, 202, 203, 207, 211, 213, 214,    218, 225, 229, 236, 237, 244, 248, 249, 251, 252, 264, 270, 280,    288, 289, 291;-   C.I. Direct Black 9, 17, 19, 22, 32, 51, 56, 62, 69, 77, 80, 91, 94,    97, 108, 112, 113, 114, 117, 118, 121, 122, 125, 132, 146, 154, 166,    168, 173, 199;-   C.I. Acid Red 35, 42, 52, 57, 62, 80, 82, 111, 114, 118, 119, 127,    128, 131, 143, 151, 154, 158, 249, 254, 257, 261, 263, 266, 289,    299, 301, 305, 336, 337, 361, 396, 397;-   C.I. Acid Violet 5, 34, 43, 47, 48, 90, 103, 126;-   C.I. Acid Yellow 17, 19, 23, 25, 39, 40, 42, 44, 49, 50, 61, 64, 76,    79, 110, 127, 135, 143, 151, 159, 169, 174, 190, 195, 196, 197, 199,    218, 219, 222, 227;-   C.I. Acid Blue 9, 25, 40, 41, 62, 72, 76, 78, 80, 82, 92, 106, 112,    113, 120, 127:1, 129, 138, 143, 175, 181, 205, 207, 220, 221, 230,    232, 247, 258, 260, 264, 271, 277, 278, 279, 280, 288, 290, 326;-   C.I. Acid Black 7, 24, 29, 48, 52:1, 172;-   C.I. Reactive Red 3, 13, 17, 19, 21, 22, 23, 24, 29, 35, 37, 40, 41,    43, 45, 49, 55;-   C.I. Reactive Violet 1, 3, 4, 5, 6, 7, 8, 9, 16, 17, 22, 23, 24, 26,    27, 33, 34;-   C.I. Reactive Yellow 2, 3, 13, 14, 15, 17, 18, 23, 24, 25, 26, 27,    29, 35, 37, 41, 42;-   C.I. Reactive Blue 2, 3, 5, 8, 10, 13, 14, 15, 17, 18, 19, 21, 25,    26, 27, 28, 29, 38;-   C.I. Reactive Black 0.4, 5, 8, 14, 21, 23, 26, 31, 32, 34;-   C.I. Basic Red 12, 13, 14, 15, 18, 22, 23, 24, 25, 27, 29, 35, 36,    38, 39, 45, 46;-   C.I. Basic Violet 1, 2, 3, 7, 10, 15, 16, 20, 21, 25, 27, 28, 35,    37, 39, 40, 48;-   C.I. Basic Yellow 1, 2, 4, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28,    29, 32, 36, 39, 40;-   C.I. Basic Blue 1, 3, 5, 7, 9, 22, 26, 41, 45, 46, 47, 54, 57, 60,    62, 65, 66, 69, 71; and-   C.I. Basic Black 8.

Pigments may be used in the ink of the present invention. In addition tocommercially available pigments, well-known pigments described invarious literature can be used. The pigments described, e.g., in TheSociety of Dyers and Colourists compiled, Color Index, Nippon GanryoGijutsu Kyokai compiled, Kaitei Shinpan Ganryo Binran (Novel PigmentHandbook, Revised Edition) (1989), Saishin Ganryo Oyo Gijutsu (TheLatest Applied Techniques of Pigments), CMC Publishing Co. (1986),Insatsu Ink Gijutsu (The techniques of Printing Inks), CMC PublishingCo. (1984), and W. Herbst and K. Hunger, Industrial Organic Pigments,VCH Verlagsgesellschaft (1993) can be exemplified. Specifically, asorganic pigments, such as azo pigments (e.g., azo lake pigments,insoluble azo pigments, condensed azo pigments, and chelate azopigments), polycyclic pigments (e.g., phthalocyanine pigments,anthraquinone pigments, perylene and perinone pigments, indigo pigments,quinacridone pigments, dioxazine pigments, isoindolinone pigments,quinophthalone pigments, and diketopyrrolopyrrole pigments), dyed lakepigments (e.g., lake pigments of acid or basic dyes), and azinepigments, and as inorganic pigments, such as yellow pigments, e.g., C.I.Pigment Yellow 34, 37, 42 and 53, red pigments, e.g., C.I. Pigment Red101 and 108, blue pigments, e.g., C.I. Pigment Blue 27, 29 and 17:1,black pigments, e.g., C.I. Pigment Black 7 and magnetite, and whitepigments, e.g., C. I. Pigment White 4, 6, 18 and 21, can be exemplified.

As the pigments having preferred tone for image formation, with respectto blue or cyan pigments, phthalocyanine pigments, anthraquinone seriesindanthrone pigments (e.g., C.I. Pigment Blue 60), and triarylcarboniumpigments of dyed lake pigments are preferably used, and phthalocyaninepigments are most preferred (the preferred examples include copperphthalocyanine, e.g., C.I. Pigment Blue 15:1, 15:2, 15:3, 15:4 and 15:6,monochlorinated or low chlorinated copper phthalocyanine, pigmentsdisclosed in EP 860475 as aluminum phthalocyanine, metal-freephthalocyanine C.I. Pigment Blue 16, and phthalocyanine having Zn, Ni orTi as the central metal, and of these pigments, C.I. Pigment Blue 15:3and 15:4 and aluminum phthalocyanine are especially preferred).

With respect to red or purple pigments, azo pigments (the preferredexamples include C.I. Pigment Red 3, 5, 11, 22, 38, 48:1, 48:2, 48:3,48:4, 49:1, 52:1, 53:1, 57:1, 63:2, 144, 146 and 184, above all, C.I.Pigment Red 57:1, 146 and 184 are preferred), quinacridone pigments (thepreferred examples include C.I. Pigment Red 122, 192, 202, 207 and 209,C.I. Pigment Violet 19 and 42, above all, C.I. Pigment Red 122 ispreferred), triarylcarbonium pigments of dyed lake series pigments (thepreferred examples include xanthene series C.I. Pigment Red 81:1, C.I.Pigment Violet 1, 2, 3, 27 and 39), dioxazine pigments (e.g., C.I.Pigment Violet 23 and 37), diketopyrrolopyrrole pigments (e.g., C.I.Pigment Red 254), perylene pigments (e.g., C.I. Pigment Violet 29),anthraquinone pigments (e.g., C.I. Pigment Violet 5:1, 31 and 33),thioindigo pigments (e.g., C.I. Pigment Red 38 and 88) are preferablyused.

With respect to yellow pigments, azo pigments (the preferred examplesinclude monoazo pigment series C.I. Pigment Yellow 1, 3, 74 and 98,disazo pigment series C.I. Pigment Yellow 12, 13, 14, 16, 17 and 83,synthesis azo series C.I. Pigment Yellow 93, 94, 95, 128 and 155, andbenzimidazolone series C.I. Pigment Yellow 120, 151, 154, 156 and 180,and pigments not using benzidine compounds as the starting material arepreferred above all), isoindoline-isoindolinone pigments (the preferredexamples include C.I. Pigment Yellow 109, 110, 137 and 139),quinophthalone pigments (the preferred example includes C.I. PigmentYellow 138), and flavanthrone pigments (e.g., C.I. Pigment Yellow 24)are preferably used.

With respect to black pigments, inorganic pigments (the preferredexamples include carbon black and magnetite), and aniline black arepreferably used.

In addition to the above pigments, orange pigments (e.g., C.I. PigmentOrange 13 and 16) and green pigments (e.g., C.I. Pigment Green 7) may beused in the present invention.

The pigments which can be used in ink set in the present invention maybe pigments having been subjected to no special treatment as describedabove or they may be surface-covered pigments. As the surface treatingmethods, a method of surface-coating with resins and waxes, a method ofadhering surfactants to pigment surfaces, and a method of bondingreactive substances (e.g., silane coupling agents, epoxy compounds,polyisocyanate, or radicals generated from diazonium salts) to pigmentsurfaces. These methods are described in the following literature andpatent specifications.

(1) Kinzoku-Sekken no Seishitsu to Oyo (Properties and Applications ofMetal Soaps), Saiwai Shobo Co.

(2) Insatsu-Ink Insatsu (Printing of Printing Inks), CMC Publishing Co.(1984)

(3) Saishin Ganryo Oyo Gijutsu (The Latest Applied Techniques ofPigments), CMC Publishing Co. (1986)

(4) U.S. Pat. Nos. 5,554,739 and 5,571,311

(5) JP-A-9-151342 (the term “JP-A” as used herein means an “unexaminedpublished Japanese patent application”), JP-A-10-140065, JP-A-10-292143and JP-A-11-166145

In particular, self-dispersible pigments prepared by making thediazonium salts disclosed in U.S. patents in (4) act on carbon black,and encapsulated pigments prepared by the methods disclosed in JP-A in(5) are particularly useful, since dispersion stability can be obtainedwithout using an extra dispersant in inks.

In the ink of the present invention, pigments may be further dispersedwith a dispersant. A variety of well-known dispersants, e.g., lowmolecular weight dispersants and high molecular weight dispersants of asurfactant type, can be used in accordance with the pigment to be used.The examples of dispersants are disclosed in JP-A-3-69949 and EP 549486.When a dispersant is used, a pigment derivative called a synergist maybe added together to accelerate the adsorption of the dispersant ontothe pigment.

The particle size of the pigments which can be used in the ink of thepresent invention is preferably from 0.01 to 10 μm after dispersion, andmore preferably from 0.05 to 1 μm.

Well-know dispersing methods used in the manufacture of inks and tonerscan be used as the dispersing methods of pigments. The examples ofdispersing apparatus include a vertical or horizontal agitator mill, anattritor, a colloid mill, a ball mill, a three-roll mill, a pearl mill,a super-mill, an impeller, a disperser, a KD mill, a dynatron, and apressure kneader. These dispersing apparatus are described in detail inSaishin Ganryo Oyo Gijutsu (The Latest Applied Techniques of Pigments),CMC Publishing Co. (1986).

As the dye which can be preferably used in magenta and light magenta, ordark yellow ink of the ink for ink jet recording of the presentinvention and is effective in image fastness and the maintenance ofcolor balance, an azo dye represented by the following formula (1)having an aromatic nitrogen-containing 6-membered heterocyclic ring asthe coupling component is exemplified.

In formula (1), A represents a 5-membered heterocyclic group.

B¹ and B² respectively represent ═CR¹— and —CR²═, or either onerepresents a nitrogen atom and the other represents ═CR¹— or —CR²═, R⁵and R⁶ each represents a hydrogen atom or a substituent, the substituentrepresents an aliphatic group, an aromatic group, a heterocyclic group,an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, acarbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, or asulfamoyl group, and the hydrogen atom of each substituent may besubstituted.

G, R¹ and R₂ each represents a hydrogen atom or a substituent, thesubstituent represents a halogen atom, an aliphatic group, an aromaticgroup, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, aheterocyclic oxycarbonyl group, an acyl group, a hydroxyl group, analkoxyl group, an aryloxy group, a heterocyclic oxy group, a silyloxygroup, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxygroup, an aryloxycarbonyloxy group, an amino group, an acylamino group,a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonylgroup, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclicsulfinyl group, a sulfamoyl group, or a sulfo group, and the hydrogenatom of each substituent may be substituted.

R¹ and R⁵, or R⁵ and R⁶ may be bonded to form a 5- or 6-membered ring.

A compound represented by formula (1) is described below in furtherdetail.

In formula (1), A represents a 5-membered heterocyclic group. N, O and Scan be exemplified as the hetero atoms of the heterocyclic ring of theheterocyclic group. The 5-membered heterocyclic group is preferably anitrogen-containing 5-membered heterocyclic group, and an aliphaticring, an aromatic ring or other heterocyclic ring may be condensed withthe heterocyclic ring. As the preferred examples of the heterocyclicrings represented by A, a pyrazole ring, an imidazole ring, a thiazolering, an isothiazole ring, a thiadiazole ring, a benzothiazole ring, abenzoxazole ring and a benzisothiazole ring can be exemplified. Eachheterocyclic group may further have a substituent. Of these, a pyrazolering, an imidazole ring, an isothiazole ring, a thiadiazole ring, and abenzothiazole ring represented by formula (a), (b), (c), (d), (e) or (f)are preferred.

In formulae (a) to (f), R⁷ to R²⁰ each represents the same substituentsas G, R¹ and R² in formula (1).

Of formulae (a) to (f), a pyrazole ring represented by formula (a) andan isothiazole ring represented by formula (b) are preferred, and apyrazole ring represented by formula (a) is most preferred.

In formula (1), B¹ and B² respectively represent ═CR¹— and —CR²═, oreither one represents a nitrogen atom and the other represents ═CR¹— or—CR²═, and more preferably B¹ and B² respectively represent ═CR¹— and—CR²═.

R⁵ and R⁶ each represents a hydrogen atom or a substituent, thesubstituent represents an aliphatic group, an aromatic group, aheterocyclic group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, anarylsulfonyl group, or a sulfamoyl group, and the hydrogen atom of eachsubstituent may be substituted.

R⁵ and R⁶ each preferably represents a hydrogen atom, an aliphaticgroup, an aromatic group, a heterocyclic group, an acyl group, analkylsulfonyl group, or an arylsulfonyl group, more preferably ahydrogen atom, an aromatic group, a heterocyclic group, an acyl group,an alkylsulfonyl group, or an arylsulfonyl group, and most preferably ahydrogen atom, an aryl group or a heterocyclic group. The hydrogen atomof each substituent may be substituted, provided that R⁵ and R⁶ do notrepresent a hydrogen atom at the same time.

G, R¹ and R₂ each represents a hydrogen atom or a substituent, thesubstituent represents a halogen atom, an aliphatic group, an aromaticgroup, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, aheterocyclic oxycarbonyl group, an acyl group, a hydroxyl group, analkoxyl group, an aryloxy group, a heterocyclic oxy group, a silyloxygroup, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxygroup, an aryloxycarbonyloxy group, an amino group, an acylamino group,a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonylgroup, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclicsulfinyl group, a sulfamoyl group, or a sulfo group, and the hydrogenatom of each substituent may be substituted.

G preferably represents a hydrogen atom, a halogen atom, an aliphaticgroup, an aromatic group, a hydroxyl group, an alkoxyl group, an aryloxygroup, an acyloxy group, a heterocyclic oxy group, an amino group, anacylamino group, a ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, an alkylthiogroup, an arylthio group, or a heterocyclic thio group, more preferablya hydrogen atom, a halogen atom, an alkyl group, a hydroxyl group, analkoxyl group, an aryloxy group, an acyloxy group, an amino group, or anacylamino group, and most preferably a hydrogen atom, an amino group(preferably an anilino group), or an acylamino group, and the hydrogenatom of each substituent may be substituted.

R¹ and R₂ each preferably represents a hydrogen atom, an alkyl group, ahalogen atom, an alkoxycarbonyl group, a carboxyl group, a carbamoylgroup, a hydroxyl group, an alkoxyl group, or a cyano group, and thehydrogen atom of each substituent may be substituted.

R¹ and R⁵, or R⁵ and R⁶ may be bonded to form a 5- or 6-membered ring.

When A has a substituent, or the substituents represented by R, R¹, R²,R⁵, R⁶ or G further have substituents, the substituents described in G,R¹ and R² are exemplified as the examples of these substituents.

When a dye represented by formula (1) is a water-soluble dye, it ispreferred that an ionic hydrophilic group is substituted anywhere on A,R¹, R², R⁵, R⁶ and G. The ionic hydrophilic group as the substituentincludes a sulfo group, a carboxyl group, a phosphono group and aquaternary ammonium group. As the ionic hydrophilic group, a carboxylgroup, a phosphono group and a sulfo group are preferred, and a carboxylgroup and a sulfo group are particularly preferred. The carboxyl group,phosphono group and sulfo group may be in the state of a salt, and theexamples of the counter ions for forming the salts include an ammoniumion, an alkali metal ion (e.g., a lithium ion, a sodium ion and apotassium ion), and an organic cation (a tetramethylammonium ion, atetramethylguanidium ion and a tetramethylsulfonium ion).

The substituents used in formula (1) are described in detail below. Themeaning of each substituent in formula (1) is common to formula (2),between different marks, too.

As the halogen atom, a fluorine ion, a chlorine ion and a bromine ionare exemplified.

The aliphatic group means an alkyl group, a substituted alkyl group, analkenyl group, a substituted alkenyl group, an alkynyl group, asubstituted alkynyl group, an aralkyl group and a substituted aralkylgroup. In the specification of the invention, “substituted” used, e.g.,in “substituted alkyl group” means that the hydrogen atom in the “alkylgroup” is substituted with a substituent exemplified in G, R¹ and R².

The aliphatic group may be branched or may form a ring. The aliphaticgroup preferably has from 1 to 20 carbon atoms, and more preferably from1 to 16. The aryl moiety of the aralkyl group and the substitutedaralkyl group is preferably a phenyl group or a naphthyl group, andparticularly preferably a phenyl group. The examples of the aliphaticgroups include a methyl group, an ethyl group, a butyl group, anisopropyl group, a t-butyl group, a hydroxyethyl group, a methoxyethylgroup, a cyanoethyl group, a trifluoromethyl group, a 3-sulfopropylgroup, a 4-sulfobutyl group, a cyclohexyl group, a benzyl group, a2-phenethyl group, a vinyl group and an allyl group.

The aromatic group means an aryl group and a substituted aryl group. Thearyl group is preferably a phenyl group or a naphthyl group, andparticularly preferably a phenyl group. The aromatic group preferablyhas from 6 to 20 carbon atoms, and more preferably from 6 to 16.

The examples of the aromatic groups include a phenyl group, a p-tolylgroup, a p-methoxyphenyl group, an o-chlorophenyl group and anm-(3-sulfopropylamino)phenyl group.

The heterocyclic group includes a substituted hetero-cyclic group. Analiphatic ring, an aromatic ring or other heterocyclic ring may becondensed with the heterocyclic ring of the heterocyclic group. Theheterocyclic group is preferably a 5- or 6-membered heterocyclic group.The examples of the substituents include an aliphatic group, a halogenatom, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, anacylamino group, a sulfamoyl group, a carbamoyl group, and an ionichydrophilic group. The examples of the heterocyclic groups include a2-pyridyl group, a 2-thienyl group, a 2-thiazolyl group, a2-benzothiazolyl group, a 2-benzoxazolyl group, and a 2-furyl group.

The carbamoyl group includes a substituted carbamoyl group. The examplesof the substituents include an alkyl group. The examples of thecarbamoyl group include a methylcarbamoyl group and a dimethylcarbamoylgroup.

The alkoxycarbonyl group includes a substituted alkoxycarbonyl group.The alkoxycarbonyl group is preferably an alkoxycarbonyl group havingfrom 2 to 20 carbon atoms. The examples of the substituents include anionic hydrophilic group. The examples of the alkoxycarbonyl groupsinclude a methoxycarbonyl group and an ethoxycarbonyl group.

The aryloxycarbonyl group includes a substituted aryloxycarbonyl group.The aryloxycarbonyl group is preferably an aryloxycarbonyl group havingfrom 7 to 20 carbon atoms. The examples of the substituents include anionic hydrophilic group. The examples of the aryloxycarbonyl groupsinclude a phenoxycarbonyl group.

The heterocyclic oxycarbonyl group includes a substituted heterocyclicoxycarbonyl group. As the examples of the heterocyclic rings, theheterocyclic rings described in the above heterocyclic group can beexemplified. The heterocyclic oxycarbonyl group is preferably aheterocyclic oxycarbonyl group having from 2 to 20 carbon atoms. Theexamples of the substituents include an ionic hydrophilic group. Theexamples of the heterocyclic oxycarbonyl groups include a2-pyridyloxycarbonyl group.

The acyl group includes a substituted acyl group. The acyl group ispreferably an acyl group having from 1 to 20 carbon atoms. The examplesof the substituents include an ionic hydrophilic group. The examples ofthe acyl groups include an acetyl group and a benzoyl group.

The alkoxyl group includes a substituted alkoxyl group. The alkoxylgroup is preferably an alkoxyl group having from 1 to 20 carbon atoms.The examples of the substituents include an alkoxyl group, a hydroxylgroup, and an ionic hydrophilic group. The examples of the alkoxylgroups include a methoxy group, an ethoxy group, an isopropoxy group, amethoxyethoxy group, a hydroxyethoxy group, and a 3-carboxypropoxygroup.

The aryloxy group includes a substituted aryloxy group. The aryloxygroup is preferably an aryloxy group having from 6 to 20 carbon atoms.The examples of the substituents include an alkoxyl group and an ionichydrophilic group. The examples of the aryloxy groups include a phenoxygroup, a p-methoxyphenoxy group and an o-methoxyphenoxy group.

The heterocyclic oxy group includes a substituted heterocyclic oxygroup. As the examples of the heterocyclic rings, the heterocyclic ringsdescribed in the above heterocyclic group can be exemplified. Theheterocyclic oxy group is preferably a heterocyclic oxy group havingfrom 2 to 20 carbon atoms. The examples of the substituents include analkyl group, an alkoxyl group and an ionic hydrophilic group. Theexamples of the heterocyclic oxy groups include a 3-pyridyloxy group anda 3-thienyloxy group.

The silyloxy group is preferably a silyloxy group having from 1 to 20carbon atoms substituted with an aliphatic group or an aromatic group.The silyloxy group includes a trimethylsilyloxy group and adiphenylmethylsilyloxy group.

The acyloxy group includes a substituted acyloxy group. The acyloxygroup is preferably an acyloxy group having from 1 to 20 carbon atoms.The examples of the substituents include an ionic hydrophilic group. Theexamples of the acyloxy groups include an acetoxy group and a benzoyloxygroup.

The carbamoyloxy group includes a substituted carbamoyloxy group. Theexamples of the substituents include an alkyl group. The examples of thecarbamoyloxy groups include an N-methylcarbamoyloxy group.

The alkoxycarbonyloxy group includes a substituted alkoxycarbonyloxygroup. The alkoxycarbonyloxy group is preferably an alkoxycarbonyloxygroup having from 2 to 20 carbon atoms. The examples of thealkoxycarbonyloxy groups include a methoxycarbonyloxy group and anisopropoxycarbonyloxy group.

The aryloxycarbonyloxy group includes a substituted aryloxycarbonyloxygroup. The aryloxycarbonyloxy group is preferably an aryloxycarbonyloxygroup having from 7 to 20 carbon atoms. The examples of thearyloxycarbonyloxy groups include a phenoxycarbonyloxy group.

The amino group includes a substituted amino group. The examples of thesubstituents include an alkyl group, an aryl group and a heterocyclicgroup. Each of the alkyl group, aryl group and heterocyclic group mayfurther have a substituent. The alkylamino group includes a substitutedalkylamino group. The alkylamino group is preferably an alkylamino grouphaving from 1 to 20 carbon atoms. The examples of the substituentsinclude an ionic hydrophilic group. The examples of the alkylaminogroups include a methylamino group and a diethylamino group.

The arylamino group includes a substituted arylamino group. Thearylamino group is preferably an arylamino group having from 6 to 20carbon atoms. The examples of the substituents include a halogen atomand an ionic hydrophilic group. The examples of the arylamino groupsinclude a phenylamino group and a 2-chlorophenylamino group.

The heterocyclic amino group includes a substituted heterocyclic aminogroup. As the examples of the heterocyclic rings, the heterocyclic ringsdescribed in the above heterocyclic group can be exemplified. Theheterocyclic amino group is preferably a heterocyclic amino group havingfrom 2 to 20 carbon atoms. The examples of the substituents include analkyl group, a halogen atom and an ionic hydrophilic group.

The acylamino group includes a substituted acylamino group. Theacylamino group is preferably an acylamino group having from 2 to 20carbon atoms. The examples of the substituents include an ionichydrophilic group. The examples of the acylamino groups include anacetylamino group, a propionylamino group, a benzoylamino group, anN-phenylacetylamino group and a 3,5-disulfobenzoylamino group.

The ureido group includes a substituted ureido group. The ureido groupis preferably a ureido group having from 1 to 20 carbon atoms. Theexamples of the substituents include an alkyl group and an aryl group.The examples of the ureido groups include a 3-methylureido group, a3,3-dimethylureido group and a 3-phenylureido group.

The sulfamoylamino group includes a substituted sulfamoylamino group.The examples of the substituents include an alkyl group. The examples ofthe sulfamoylamino groups include an N,N-dipropylsulfamoylamino group.

The alkoxycarbonylamino group includes a substituted alkoxycarbonylaminogroup. The alkoxycarbonylamino group is preferably analkoxycarbonylamino group having from 2 to 20 carbon atoms. The examplesof the substituents include an ionic hydrophilic group. The examples ofthe alkoxycarbonyl-amino groups include an ethoxycarbonylamino group.

The aryloxycarbonylamino group includes a substitutedaryloxycarbonylamino group. The aryloxycarbonylamino group is preferablyan aryloxycarbonylamino group having from 7 to 20 carbon atoms. Theexamples of the substituents include an ionic hydrophilic group. Theexamples of the aryloxy-carbonylamino groups include aphenoxycarbonylamino group.

The alkylsulfonylamino group and the arylsulfonylamino group include asubstituted alkylsulfonylamino group and a substituted arylsulfonylaminogroup. The alkylsulfonylamino group and the arylsulfonylamino group arepreferably an alkylsulfonylamino group and an arylsulfonylamino groupeach having from 1 to 20 carbon atoms. The examples of the substituentsinclude an ionic hydrophilic group. The examples of thealkylsulfonylamino groups and the arylsulfonylamino groups include amethylsulfonylamino group, an N-phenylmethylsulfonylamino group, aphenylsulfonylamino group, and a 3-carboxyphenylsulfonylamino group.

The heterocyclic sulfonylamino group includes a substituted heterocyclicsulfonylamino group. As the examples of the heterocyclic rings, theheterocyclic rings described in the above heterocyclic group can beexemplified. The heterocyclic sulfonylamino group is preferably aheterocyclic sulfonylamino group having from 1 to 12 carbon atoms. Theexamples of the substituents include an ionic hydrophilic group. Theexamples of the heterocyclic sulfonylamino groups include a2-thienylsulfonylamino group and a 3-pyridylsulfonylamino group.

The alkylthio group, the arylthio group and the heterocyclic thio groupinclude a substituted alkylthio group, a substituted arylthio group anda substituted heterocyclic thio group. As the examples of theheterocyclic rings, the heterocyclic rings described in the aboveheterocyclic group can be exemplified. The alkylthio group, the arylthiogroup and the heterocyclic thio group are preferably an alkylthio group,an arylthio group and a heterocyclic thio group each having from 1 to 20carbon atoms. The examples of the substituents include an ionichydrophilic group. The examples of the alkylthio groups, the arylthiogroups and the heterocyclic thio groups include a methylthio group, aphenylthio group, and a 2-pyridylthio group.

The alkylsulfonyl group and the arylsulfonyl group include a substitutedalkylsulfonyl group and a substituted arylsulfonyl group. The examplesof the alkylsulfonyl groups and the arylsulfonyl groups include amethylsulfonyl group and a phenylsulfonyl group, respectively.

The heterocyclic sulfonyl group includes a substituted heterocyclicsulfonyl group. As the examples of the heterocyclic rings, theheterocyclic rings described in the above heterocyclic group can beexemplified. The heterocyclic sulfonyl group is preferably aheterocyclic sulfonyl group having from 1 to 20 carbon atoms. Theexamples of the substituents include an ionic hydrophilic group. Theexamples of the heterocyclic sulfonyl groups include a 2-thienylsulfonylgroup and a 3-pyridylsulfonyl group.

The alkylsulfinyl group and the arylsulfinyl group include a substitutedalkylsulfinyl group and a substituted arylsulfinyl group. The examplesof the alkylsulfinyl groups and the arylsulfinyl groups include amethylsulfinyl group and a phenylsulfinyl group, respectively.

The heterocyclic sulfinyl group includes a substituted heterocyclicsulfinyl group. As the examples of the heterocyclic rings, theheterocyclic rings described in the above heterocyclic group can beexemplified. The heterocyclic sulfinyl group is preferably aheterocyclic sulfinyl group having from 1 to 20 carbon atoms. Theexamples of the substituents include an ionic hydrophilic group. Theexamples of the heterocyclic sulfinyl groups include a 4-pyridylsulfinylgroup.

The sulfamoyl group includes a substituted sulfamoyl group. The examplesof the substituents include an alkyl group. The examples of thesulfamoyl groups include a dimethylsulfamoyl group and adi(2-hydroxyethyl)sulfamoyl group.

A dye represented by formula (1) for use in the ink of the invention isparticularly preferably represented by the following formula (2).

In formula (2), R¹, R², R⁵ and R⁶ each has the same meaning as informula (1).

R³ and R₄ each represents a hydrogen atom or a substituent, and thesubstituent represents an aliphatic group, an aromatic group, aheterocyclic group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, anarylsulfonyl group, or a sulfamoyl group. Of these groups, a hydrogenatom, an aromatic group, a heterocyclic group, an acyl group, analkylsulfonyl group and an arylsulfonyl group are preferred, and ahydrogen atom, an aromatic group, a heterocyclic group are particularlypreferred.

Z¹ represents an electron attractive group having Hammett's substitutionconstant σp value of 0.20 or higher. Z¹ is preferably an electronattractive group having a σp value of 0.30 or higher, more preferably anelectron attractive group of 0.45 or higher, and particularly preferablyan electron attractive group of 0.60 or higher but preferably not higherthan 1.0. The preferred specific examples of the substituents are thelater-described electron attractive substituents, and an acyl grouphaving from 2 to 20 carbon atoms, an alkyloxycarbonyl group having from2 to 20 carbon atoms, a nitro group, a cyano group, an alkylsulfonylgroup having from 1 to 20 carbon atoms, an arylsulfonyl group havingfrom 6 to 20 carbon atoms, a carbamoyl group having from 1 to 20 carbonatoms, and an alkyl halide having from 1 to 20 carbon atoms arepreferred, a cyano group, an alkylsulfonyl group having from 1 to 20carbon atoms, and an arylsulfonyl group having from 6 to 20 carbon atomsare particularly preferred, and a cyano group is most preferred.

Z² represents a hydrogen atom or a substituent, and the substituentrepresents an aliphatic group, an aromatic group, or a heterocyclicgroup. Z² preferably represents an aliphatic group, and more preferablyan alkyl group having from 1 to 6 carbon atoms.

Q represents a hydrogen atom or a substituent, and the substituentrepresents an aliphatic group, an aromatic group, or a heterocyclicgroup, and preferably a group of non-metal atom necessary to form 5- to8-membered rings. The 5- to 8-membered rings may be substituted, may besaturated rings, or may have an unsaturated bond. An aromatic group anda heterocyclic group are particularly preferred. The preferred examplesof the non-metal atoms include a nitrogen atom, an oxygen atom, a sulfuratom or a carbon atom. The specific examples of such cyclic structuresinclude, e.g., a benzene ring, a cyclopentane ring, a cyclohexane ring,a cycloheptane ring, a cyclooctane ring, a cyclohexene ring, a pyridinering, a pyrimidine ring, a piperazine ring, a pyridazine ring, atriazine ring, an imidazole ring, a benzimidazole ring, an oxazole ring,a benzoxazole ring, a thiazole ring, a benzothiazole ring, an oxan ring,a sulforan ring and a thian ring.

The hydrogen atom of each substituent described in formula (2) may besubstituted. The examples of the substituents include the substituentsdescribed in formula (1), the substituents described in G, R¹ and R²,and an ionic hydrophilic group.

A Hammett's substitution constant σp value described in thisspecification is explained below. Hammett's rule is a rule of thumbsuggested by L. P. Hammett in 1935 to quantitatively discuss theinfluence of a substituent on the reaction or equilibrium of a benzenederivative, and the appropriateness of the rule is now widelyrecognized. There are substitution constant σp value and σm valueobtained by Hammett's rule, and these values can be found in a largeliterature, e.g., J. A. Dean compiled, Lange's Handbook of Chemistry,12th Ed., McGraw Hill (1979), and Kagaku no Ryoiki (The Domain ofChemistry), Extra Issue, No. 122, pp. 96 to 103, Mankodo (1979). In thepresent invention, each substituent is restricted or explained byHammett's substitution constant σp, but it does not mean that analready-known value is limited to only a certain substituent. It is amatter of course that even if a value is unknown, a substituent whosevalue will be included in that range when measured on the basis ofHammett's rule is also included. Compounds which are not benzenederivatives are also included in formula (2) of the invention, but σpvalue is used regardless of the substitution position as the criterionshowing the electron effect of substituents. σp Value is used in such amean in the present invention.

As the electron attractive groups having Hammett's substitution constantσp value of 0.60 or higher, a cyano group, a nitro group, analkylsulfonyl group (e.g., a methylsulfonyl group), and an arylsulfonylgroup (e.g., a phenylsulfonyl group) can be exemplified.

As the electron attractive groups having Hammett's substitution constantσp value of 0.45 or higher, in addition to the above groups, acyl group(e.g., an acetyl group), an alkoxycarbonyl group (e.g.,dodecyloxycarbonyl group), an aryloxycarbonyl group (e.g., anm-chlorophenoxycarbonyl group), an alkylsulfinyl group (e.g., ann-propylsulfinyl group), an arylsulfinyl group (e.g., a phenylsulfinylgroup), a sulfamoyl group (e.g., an N-ethylsulfamoyl group and anN,N-dimethylsulfamoyl group), and an alkyl halide group (e.g., atrifluoromethyl group) can be exemplified.

As the electron attractive groups having Hammett's substitution constantσp value of 0.30 or higher, in addition to the above groups, an acyloxygroup (e.g., an acetoxy group), a carbamoyl group (e.g., anN-ethylcarbamoyl group and N,N-dibutylcarbamoyl group), an alkoxylhalide group (e.g., a trifluoromethyloxy group), an aryloxy halide group(e.g., a pentafluorophenyloxy group), a sulfonyloxy group (e.g., amethylsulfonyloxy group), an alkylthio halide group (e.g., adifluoromethylthio group), an aryl group substituted with 2 or moreelectron attractive groups having σp value of 0.15 or higher (e.g., a2,4-dinitrophenyl group and a pentachlorophenyl group), and aheterocyclic group (e.g., a 2-benzoxazolyl group, a 2-benzothiazolylgroup, a 1-phenyl-2-benzimidazolyl group) can be exemplified.

As the electron attractive groups having Hammett's substitution constantσp value of 0.20 or higher, in addition to the above groups, a halogenatom can be exemplified.

As the azo dye represented by formula (1), particularly preferredcombinations of substituents are described. The preferred groups as R⁵and R⁶ are a hydrogen atom, an alkyl group, an aryl group, aheterocyclic group, a sulfonyl group and an acyl group, more preferredgroups are a hydrogen atom, an aryl group, a heterocyclic group, and asulfonyl group, and most preferred groups are a hydrogen atom, an arylgroup, and a heterocyclic group, provided that R⁵ and R⁶ do notrepresent a hydrogen atom at the same time.

The preferred groups as G are a hydrogen atom, a halogen atom, an alkylgroup, a hydroxyl group, an amino group and an acylamino group, morepreferred groups are a hydrogen atom, a halogen atom, an amino group andan acylamino group, and most preferred groups are a hydrogen atom, anamino group and an acylamino group.

The preferred groups as A are a pyrazole ring, an imidazole ring, anisothiazole ring, a thiadiazole ring, and a benzothiazole ring, morepreferred groups are a pyrazole ring and an isothiazole ring, and mostpreferred group is a pyrazole ring.

As the preferred combination of B¹ and B², B¹ and B² respectivelyrepresent ═CR¹— and —CR²═, R¹ and R² each preferably represents ahydrogen atom, an alkyl group, a halogen atom, a cyano group, acarbamoyl group, a carboxyl group, a hydroxyl group, an alkoxyl group,or an alkoxycarbonyl group, and more preferably a hydrogen atom, analkyl group, a carboxyl group, a cyano group, or a carbamoyl group.

Regarding the preferred combinations of the substituents of the compoundrepresented by formula (1), a compound in which at least one of varioussubstituents is the above preferred group is preferred, a compound inwhich a greater number of substituents are the above preferred groups ismore preferred, and a compound in which all the substituents are theabove preferred groups is most preferred.

The specific examples of the azo dyes represented by formula (1) areshown below, but the azo dyes for use in the present invention are notlimited thereto.

TABLE 1

R₁ R₂ R₃ a-1

a-2

a-3

a-4

a-5

TABLE 2

R₁ R₂ R₃ a-6

a-7

a-8

a-9

C₈H₁₇(t) a-10

TABLE 3

R₁ R₂ R₃ R₄ a-11

a-12

a-13

a-14

a-15

a-16

a-17

TABLE 4

R₁ R₂ R₃ R₄ a-18

a-19

—SO₂CH₃

a-20

—COCH₃ C₈H₁₇(t) C₈H₁₇(t) a-21

—SO₂CH₃

C₈H₁₇(t) a-22

H

a-23

H

a-24

H

a-25

a-26

a-27

a-28

a-29

a-30

C₈H₁₇(t) a-31

a-32

a-33

a-34

a-35

R₁ R₂ R₃ R₄ a-36

a-37

a-38

a-39

a-40

R₁ R₂ R₃ R₄ R₅ R₆ R₇ R₈ a-41

CN

H CONH₂ SO₂CH₃

a-42

Br

COOEt H

C₈H₁₇(t) COCH₃ A-43

SO₂CH₃

CONH₂ H

a-44

CN

H H

SO₂CH₃ a-45

Br

H CONH₂

a-46

CN

CH₃ H

R₁ R₂ R₃ R₄ R₅ R₆ b-1 CH₃ CH₃ CN H

b-2 CH₃ CH₃ CN H

b-3 CH₃ CH₃ CONH₂ H

b-4 CH₃ CH₃ H H

b-5 CH₃ H CN H

b-6 CH₃ CH₃ H

b-7 CH₃ CH₃ H

b-8 CH₃ H H SO₂CH₃

R₁ R₂ R₃ R₄ R₅ R₆ c-1 —SCH₃ CH₃ CN H C₈H₁₇(t)

c-2

H CONH₂ H

c-3

CH₃ H

c-4 —CH₃ CH₃ H

c-5

H H

C₈H₁₇(t)

R₁ R₂ R₃ R₄ R₅ R₆ d-1 Me CH₃ CN H

d-2 Me CH₃ CN H

d-3 Me H H

d-4 Ph CH₃ CONH₂ H

d-5 Ph CH₃ H

R₁ R₂ R₃ R₄ R₅ R₆ e-1 5-Cl CH₃ CONH₂ H C₈H₁₇(t) C₈H₁₇(t) e-2 5,6-diCl HH

e-3 5,6-diCl CH₃ H

COCH₃ e-4 5-CH₃ H CN H

e-5 5-NO₂ CH₃ H SO₂CH₃

f-1

f-2

As the cyan dyes which can be preferably used in cyan and light cyan, ordark yellow ink of the ink for ink jet recording of the presentinvention, and is effective in image fastness and the maintenance ofcolor balance, a cyan dye represented by the following formula (I) isparticularly preferred.

In formula (I), X₁, X₂, X₃ and X₄ each represents —SO-Z, —SO₂-Z,—SO₂NR₁R₂, a sulfo group, —CONR₁R₂, or —CO₂R₁. Z represents asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedcycloalkyl group, a substituted or unsubstituted alkenyl group, asubstituted or unsubstituted aralkyl group, a substituted orunsubstituted aryl group, or a substituted or unsubstituted heterocyclicgroup. R₁ and R₂ each represents a hydrogen atom, a substituted orunsubstituted alkyl group, a substituted or unsubstituted cycloalkylgroup, a substituted or unsubstituted alkenyl group, a substituted orunsubstituted aralkyl group, a substituted or unsubstituted aryl group,or a substituted or unsubstituted heterocyclic group. When a pluralityof Z are present, they may be the same or different. Y₁, Y₂, Y₃ and Y₄each represents a monovalent substituent. When any of X₁, X₂, X₃, X₄,Y₁, Y₂, Y₃ and Y₄ is present in plural number, they may be the same ordifferent. M represents a hydrogen atom, a metal atom or oxide thereof,hydroxide or halide.

a₁, to a₄, and b₁ to b₄ each represents the number of substituents of X₁to X₄, and Y₁ to Y₄, respectively, a₁, a₂, a₃ and a₄ each represents 0or an integer of from 1 to 4, and all of a₁, a₂, a₃ and a₄ do notrepresent 0 at the same time, and b₁, b₂, b₃ and b₄ each represents 0 oran integer of from 1 to 4.

A compound represented by formula (I) is described below in more detail.

In formula (I), X₁, X₂, X₃ and X₄ each represents —SO—Z, —SO₂—Z,—SO₂NR₁R₂, a sulfo group, —CONR₁R₂, or —CO₂R₁. Of these substituents,—SO—Z, —SO₂—Z, —SO₂NR₁R₂ and —CONR₁R₂ are preferred, —SO₂—Z and—SO₂NR₁R₂ are particularly preferred, and —SO₂—Z is most preferred. Whenany of a₁, a₂, a₃ and a₄ showing the number of substituents representsan integer of 2 or more, a plurality of substituents of X₁ to X₄ may bethe same or different, and each represents any of the above groups. Allof X₁, X₂, X₃ and X₄ may represent absolutely the same substituent, orthe same kind of substituent may be partially different from each other,e.g., as in the case where all of X₁, X₂, X₃ and X₄ represent —SO₂—Z andZ is different from each other, or X₁, X₂, X₃ and X₄ may representdifferent substituents, e.g., —SO₂—Z and —SO₂NR₁R₂.

Z represents a substituted or unsubstituted alkyl group, a substitutedor unsubstituted cycloalkyl group, a substituted or unsubstitutedalkenyl group, a substituted or unsubstituted aralkyl group, asubstituted or unsubstituted aryl group, or a substituted orunsubstituted heterocyclic group, preferably a substituted orunsubstituted alkyl group, a substituted or unsubstituted aryl group, ora substituted or unsubstituted heterocyclic group, and most preferably asubstituted alkyl group, a substituted aryl group, or a substitutedheterocyclic group.

R₁ and R₂ each represents a hydrogen atom, a substituted orunsubstituted alkyl group, a substituted or unsubstituted cycloalkylgroup, a substituted or unsubstituted alkenyl group, a substituted orunsubstituted aralkyl group, a substituted or unsubstituted aryl group,or a substituted or unsubstituted heterocyclic group, preferably ahydrogen atom, a substituted or unsubstituted alkyl group, a substitutedor unsubstituted aryl group, or a substituted or unsubstitutedheterocyclic group, and more preferably a hydrogen atom, a substitutedalkyl group, a substituted aryl group, or a substituted heterocyclicgroup, but it is not preferred for both R₁ and R₂ to represent ahydrogen atom.

As the substituted or unsubstituted alkyl group represented by R₁, R₂and Z, an alkyl group having from 1 to 30 carbon atoms is preferred. Abranched alkyl group is preferred for being capable of increasing thesolubility of dye and the stability of ink, and the case where the alkylgroup has an a symmetric carbon atom (use as racemic modification) isparticularly preferred. As the examples of the substituents, the samesubstituents as in the case where Z, R₁, R₂, Y₁, Y₂, Y₃ and Y₄ canfurther have a substituent as described later are exemplified. Ahydroxyl group, an ether group, an ester group, a cyano group, an amidogroup and a—sulfonamido group are particularly preferred for capable ofimproving the aggregation and fastness of a dye. Besides these group, ahalogen atom and an ionic hydrophilic group may be contained assubstituents. The number of carbon atoms of a substituent is notincluded into the number of the alkyl group, and this is also applied toother groups.

As the substituted or unsubstituted cycloalkyl group represented by R₁,R₂ and Z, a cycloalkyl group having from 5 to 30 carbon atoms ispreferred. The case where the cyclo-alkyl group has an asymmetric carbonatom (use as racemic modification) is preferred for being capable ofincreasing the solubility of dye and the stability of ink. As theexamples of the substituents, the same substituents as in the case whereZ, R₁, R₂, Y₁, Y₂, Y₃ and Y₄ can further have a substituent as describedlater are exemplified. A hydroxyl group, an ether group, an ester group,a cyano group, an amido group and a sulfonamido group are particularlypreferred for capable of improving the aggregation and fastness of adye. Besides these group, a halogen atom and an ionic hydrophilic groupmay be contained as substituents.

As the substituted or unsubstituted alkenyl group represented by R₁, R₂and Z, an alkenyl group having from 2 to 30 carbon atoms is preferred. Abranched alkenyl group is preferred for being capable of increasing thesolubility of dye and the stability of ink, and the case where thealkenyl group has an asymmetric carbon atom (use as racemicmodification) is particularly preferred. As the examples of thesubstituents, the same substituents as in the case where Z, R₁, R₂, Y₁,Y₂, Y₃ and Y₄ can further have a substituent as described later areexemplified. A hydroxyl group, an ether group, an ester group, a cyanogroup, an amido group and a sulfonamido group are particularly preferredfor capable of improving the aggregation and fastness of a dye. Besidesthese group, a halogen atom and an ionic hydrophilic group may becontained as substituents.

As the substituted or unsubstituted aralkyl group represented by R₁, R₂and Z, an aralkyl group having from 7 to 30 carbon atoms is preferred. Abranched aralkyl group is preferred for being capable of increasing thesolubility of dye and the stability of ink, and the case where thearalkyl group has an asymmetric carbon atom (use as racemicmodification) is particularly preferred. As the examples of thesubstituents, the same substituents as in the case where Z, R₁, R₂, Y₁,Y₂, Y₃ and Y₄ can further have a substituent as described later areexemplified. A hydroxyl group, an ether group, an ester group, a cyanogroup, an amido group and a sulfonamido group are particularly preferredfor capable of improving the aggregation and fastness of a dye. Besidesthese group, a halogen atom and an ionic hydrophilic group may becontained as substituents.

As the substituted or unsubstituted aryl group represented by R₁, R₂ andZ, an aryl group having from 6 to 30 carbon atoms is preferred. As theexamples of the substituents, the same substituents as in the case whereZ, R₁, R₂, Y₁, Y₂, Y₃ and Y₄ can further have a substituent as describedlater are exemplified. An electron attractive group is particularlypreferred for capable of making oxidation potential of a dye noble andimproving fastness of a dye. As the electron attractive groups, thosehaving a Hammett's substitution constant σp value of positive value areexemplified, e.g., a halogen atom, a heterocyclic group, a cyano group,a carboxyl group, an acylamino group, a sulfonamido group, a sulfamoylgroup, a carbamoyl group, a sulfonyl group, an imido group, an acylgroup, a sulfo group, and a quaternary ammonium group are preferablyused as the electron attractive group, and a cyano group, a carboxylgroup, a sulfamoyl group, a carbamoyl group, a sulfonyl group, an imidogroup, an acyl group, a sulfo group, and a quaternary ammonium group aremore preferably used.

As the heterocyclic group represented by R₁, R₂ and Z, 5- or 6-memberedring groups are preferred, and they may be further condensed. The ringsmay be aromatic heterocyclic rings or non-aromatic heterocyclic rings.The examples of the heterocyclic groups represented by R₁, R₂ and Z areexemplified below in the form of heterocyclic rings, and thesubstitution positions are eliminated, but the substitution position isnot limitative, e.g., pyridine can be substituted on 2-position,3-position and 4-position. As the examples, pyridine, pyrazine,pyrimidine, pyridazine, triazine, quinoline, isoquinoline, quinazoline,cinnolin, phthalazine, quinoxaline, pyrrole, indole, furan, benzofuran,thiophene, benzothiophene, pyrazole, imidazole, benzimidazole, triazole,oxazole, benzoxazole, thiazole, benzothiazole, isothiazole,benzisothiazole, thiadiazole, isooxazole, benzisooxazole, pyrrolidine,piperidine, piperazine, imidazolidine and thiazoline are exemplified.Aromatic heterocyclic groups are particularly preferred, and thepreferred examples include, e.g., pyridine, pyrazine, pyrimidine,pyridazine, triazine, pyrazole, imidazole, benzimidazole, triazole,thiazole, benzothiazole, isothiazole, benzisothiazole and thiadiazole.These heterocyclic rings may have substituents. As the examples of thesubstituents, the same substituents as in the case where Z, R₁, R₂, Y₁,Y₂, Y₃ and Y₄ can further have a substituent as described later areexemplified. The preferred substituents and the more preferredsubstituents are the same with the preferred substituents and the morepreferred substituents of the aryl group respectively.

Y₁, Y₂, Y₃ and Y₄ each represents a hydrogen atom, a halogen atom, analkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, anaryl group, a heterocyclic group, a cyano group, a hydroxyl group, anitro group, an amino group, an alkylamino group, an alkoxyl group, anaryloxy group, an acylamino group, an arylamino group, a ureido group, asulfamoylamino group, an alkylthio group, an arylthio group, analkoxycarbonylamino group, a sulfonamido group, a carbamoyl group, asulfamoyl group, a sulfonyl group, an alkoxycarbonyl group, aheterocyclic oxy group, an azo group, an acyloxy group, a carbamoyloxygroup, a silyloxy group, an aryloxycarbonyl group, anaryloxycarbonylamino group, an imido group, a heterocyclic thio group, aphosphoryl group, an acyl group, a carboxyl group, or a sulfo group.Each group may further have a substituent.

Of these group, a hydrogen atom, a halogen atom, an alkyl group, an arylgroup, a cyano group, an alkoxyl group, an amido group, a ureido group,a sulfonamido group, a carbamoyl group, a sulfamoyl group, analkoxycarbonyl group, a carboxyl group, and a sulfo group are preferred,a hydrogen atom, a halogen atom, a cyano group, a carboxyl group, and asulfo group are particularly preferred, and a hydrogen atom is mostpreferred.

When Z, R₁, R₂, Y₁, Y₂, Y₃ and Y₄ represent substituents capable ofhaving further substituent, the following substituents may be used.

A straight or branched chain alkyl group having from 1 to 12 carbonatoms, a straight or branched chain aralkyl group having from 7 to 18carbon atoms, a straight or branched chain alkenyl group having from 2to 12 carbon atoms, a straight or branched chain alkynyl group havingfrom 2 to 12 carbon atoms, a straight or branched chain cycloalkyl grouphaving from 3 to 12 carbon atoms, a straight or branched chaincycloalkenyl group having from 3 to 12 carbon atoms (the above groupshaving a branched chain are preferred for being capable of increasingthe solubility of dye and the stability of ink, and groups having anasymmetric carbon atom are particularly preferred, and the specificexamples of these groups include, e.g., a methyl group, an ethyl group,a propyl group, an isopropyl group, a sec-butyl group, a t-butyl group,a 2-ethylhexyl group, a 2-methylsulfonylethyl group, a 3-phenoxypropylgroup, a trifluoromethyl group and a cyclopentyl group), a halogen atom(e.g., chlorine and bromine), an aryl group (e.g., a phenyl group, a4-t-butylphenyl group and a 2,4-di-t-amylphenyl group), a heterocyclicgroup (e.g., an imidazolyl group, a pyrazolyl group, a triazolyl group,a 2-furyl group, a 2-thienyl group, a 2-pyrimidinyl group and a2-benzothiazolyl group), a cyano group, a hydroxyl group, a nitro group,a carboxyl group, an amino group, an alkyloxy group (e.g., a methoxygroup, an ethoxy group, a 2-methoxyethoxy group, and a2-methanesulfonylethoxy group), an aryloxy group (e.g., a phenoxy group,a 2-methylphenoxy group, a 4-t-butylphenoxy group, a 3-nitrophenoxygroup, a 3-t-butyloxycarbamoylphenoxy group, and a 3-methoxycarbamoylgroup), an acylamino group (e.g., an acetamido group, a benzamido group,and a 4-(3-t-butyl-4-hydroxyphenoxy)butanamido group), an alkylaminogroup (e.g., a methylamino group, a butylamino group, a diethylaminogroup, and a methylbutylamino group), an anilino group (e.g., aphenylamino group and a 2-chloroanilino group), a ureido group (e.g., aphenylureido group, a methylureido group, and an N,N-dibutylureidogroup), a sulfamoylamino group (e.g., an N,N-dibropylsulfamoylaminogroup), an alkylthio group (e.g., a methylthio group, an octylthiogroup, and a 2-phenoxyethylthio group), an arylthio group (e.g., aphenylthio group, a 2-butoxy-5-t-octylphenylthio group, and a2-carboxyphenylthio group), an alkyloxycarbonylamino group (e.g., amethoxycarbonylamino group), a sulfonamido group (e.g., amethanesulfonamido group, a benzenesulfonamido group and ap-toluenesulfonamido group), a carbamoyl group (e.g., anN-ethylcarbamoyl group and an N,N-dibutylcarbamoyl group), a sulfamoylgroup (e.g., an N-ethylsulfamoyl group, an N,N-dipropylsulfamoyl group,and an N-phenylsulfamoyl group), a sulfonyl group (e.g., amethane-sulfonyl group, an octanesulfonyl group, a benzenesulfonylgroup, and a toluenesulfonyl group), an alkyloxycarbonyl group (e.g., amethoxycarbonyl group and a butyloxycarbonyl group), a heterocyclic oxygroup (e.g., a 1-phenyltetrazol-5-oxy group and a 2-tetrahydropyranyloxygroup), an azo group (e.g., a phenylazo group, a 4-methoxyphenylazogroup, a 4-pivaloylaminophenylazo group, a2-hydroxy-4-propanoylphenylazo group), an acyloxy group (e.g., anacetoxy group), a carbamoyloxy group (e.g., an N-methylcarbamoyloxygroup and an N-phenylcarbamoyloxy group), a silyloxy group (e.g., atrimethylsilyloxy group and a dibutylmethylsilyloxy group), anaryloxycarbonylamino group (e.g., a phenoxycarbonylamino group), animido group (e.g., an N-succinimido group, and an N-phthalimido group),a heterocyclic thio group (e.g., a 2-benzothiazolylthio group, a2,4-diphenoxy-1,3,5-triazol-6-thio group, and a 2-pyridylthio group), asulfinyl group (e.g., a 3-phenoxypropyl-sulfinyl group), a phosphonylgroup (e.g., a phenoxyphosphonyl group, an octyloxyphosphonyl group anda phenylphosphonyl group), an aryloxycarbonyl group (e.g., aphenoxycarbonyl group), an acyl group (e.g., an acetyl group, a3-phenylpropanoyl group and a benzoyl group), an ionic hydrophilic group(e.g., a carboxyl group, a sulfo group, a phosphono group, and aquaternary ammonium group).

When a phthalocyanine dye represented by formula (I) is a water-solubledye, it is preferred to have an ionic hydrophilic group. The ionichydrophilic group includes a sulfo group, a carboxyl group, a phosphonogroup, and a quaternary ammonium group. As the ionic hydrophilic group,a carboxyl group, a phosphono group, and a sulfo group are preferred,and a carboxyl group and a sulfo group are particularly preferred. Thecarboxyl group, phosphono group and sulfo group may be in the state of asalt, and the examples of the counter ions for forming the salts includean ammonium ion, an alkali metal ion (e.g., a lithium ion, a sodium ionand a potassium ion), and an organic cation (a tetramethylammonium ion,a tetramethylguanidium ion and a tetramethylsulfonium ion). Of thecounter ions, alkali metal ions are preferred, and a lithium ion isparticularly preferred for being capable of increasing the solubility ofdye and the stability of ink.

It is preferred that at least two ionic hydrophilic groups are containedin one molecule of a phthalocyanine dye, and it is particularlypreferred that at least two sulfo group and/or carboxyl group arecontained.

a₁ to a₄, and b₁ to b₄ each represents the number of substituents of X₁to X₄, and Y₁ to Y₄, respectively, a₁, a₂, a₃ and a₄ each represents 0or an integer of from 1 to 4, and all of a₁, a₂, a₃ and a₄ do notrepresent 0 at the same time, and b₁, b₂, b₃ and b₄ each represents 0 oran integer of from 1 to 4. When any of a₁ to a₄ and b₁ to b₄ representsan integer of 2 or more, any of X₁ to X₄ and Y₁ to Y₄ is present in aplural number, and they may be the same or different.

a₁ and b₁ satisfy the relationship of a₁+b_(l)=4. Such a combination asa₁ represents 1 or 2 and b₁ represents 3 or 2 is particularly preferred,and a combination that a₁ represents 1 and b₁ represents 3 is mostpreferred.

The combinations of a₂ and b₂, a₃ and b₃, and a₄ and b₄ have also thesame relationship as in the combination of a₁ and b₁, and preferredcombinations are also the same.

M represents a hydrogen atom, a metal element or oxide thereof,hydroxide or halide.

Besides a hydrogen atom, M preferably represents, as metal elements, Li,Na, K, Mg, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Ru, Rh, Pd, Os,Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Si, Ge, Sn, Pb, Sb and Bi.As oxide, VO and GeO are preferred. As hydroxide, Si(OH)₂, Cr(OH)₂ andSn(OH)₂ are preferred. As halide, AlCl, SiCl₂, VCl, VCl₂, VOCl, FeCl,GaCl and ZrCl are exemplified. Cu, Ni, Zn and Al are especiallypreferred, and Cu is most preferred.

Pc (a phthalocyanine ring) may form a dimer (e.g., Pc-M-L-M-Pc) or atrimer via L (a divalent linking group), and M at that time may be thesame or different.

As a divalent linking group represented by L, oxy group-O—, thiogroup-S—, carbonyl group-CO—, sulfonyl group-SO₂—, imino group-NH—,methylene group-CH₂—, and groups formed by combining these groups arepreferred.

With respect to the preferred combinations of the substituents of acompound represented by formula (I), a compound in which at least one ofvarious substituents is the above preferred group is preferred, acompound in which a greater number of various substituents are the abovepreferred groups is more preferred, and a compound in which all thesubstituents are the above preferred groups is most preferred.

A phthalocyanine dye represented by formula (I) is more preferablyrepresented by formula (II). A phthalocyanine dye represented by formula(II), which is preferably used in the present invention, is described indetail below.

In formula (II), X₁₁ to X₁₄ and Y₁₁ to Y₁₈ have the same meaning with X₁to X₄ and Y₁ to Y₄ in formula (I) respectively, and the preferredexamples are also the same. M has the same meaning with M in formula(I), and the preferred examples are also the same.

In formula (II), a₁₁ to a₁₄ each represents an integer of 1 or 2,preferably a₁₁+a₁₂+a₁₃+a₁₄ is 4 or more and 6 or less, and particularlypreferably a₁₁=a₁₂=a₁₃=a₁₄=1.

All of X₁₁, X₁₂, X₁₃ and X₁₄ may represent absolutely the samesubstituent, or the same kind of substituent may be partially differentfrom each other, e.g., as in the case where all of X₁, X₁₂, X₁₃ and X₁₄represent —SO₂—Z and Z is different from each other, or X₁₁, X₁₂, X₁₃and X₁₄ may represent different substituents, e.g., —SO₂—Z and—SO₂NR₁R₂.

Of the phthalocyanine dyes represented by formula (II), particularlypreferred combinations of the substituents are as follows.

X₁₁, X₁₂, X₁₃ and X₁₄ each preferably represents —SO—Z, —SO₂—Z,—SO₂NR₁R₂, or —CONR₁R₂, particularly preferably —SO₂—Z and —SO₂NR₁R₂,and most preferably —SO₂—Z.

Z preferably represents a substituted or unsubstituted alkyl group, asubstituted or unsubstituted aryl group, or a substituted orunsubstituted heterocyclic group, and most preferably a substitutedalkyl group, a substituted aryl group, or a substituted heterocyclicgroup. The case where the substituent has an asymmetric carbon atom (useas racemic modification) is preferred for being capable of increasingthe solubility of dye and the stability of ink. The case where thesubstituent has a hydroxyl group, an ether group, an ester group, acyano group, an amido group and a sulfonamido group is preferred forcapable of improving the aggregation and fastness of a dye.

R₁ and R₂ each preferably represents a hydrogen atom, a substituted orunsubstituted alkyl group, a substituted or unsubstituted aryl group, ora substituted or unsubstituted heterocyclic group, and more preferably ahydrogen atom, a substituted alkyl group, a substituted aryl group, or asubstituted heterocyclic group, but it is not preferred for both R₁ andR₂ to represent a hydrogen atom. The case where the substituent has anasymmetric carbon atom (use as racemic modification) is preferred forbeing capable of increasing the solubility of dye and the stability ofink. The case where the substituent has a hydroxyl group, an ethergroup, an ester group, a cyano group, an amido group and a sulfonamidogroup is preferred for capable of improving the aggregation and fastnessof a dye.

Y₁₁ to Y₁₈ each preferably represents a hydrogen atom, a halogen atom,an alkyl group, an aryl group, a cyano group, an alkoxyl group, an amidogroup, a ureido group, a sulfonamido group, a carbamoyl group, asulfamoyl group, an alkoxycarbonyl group, a carboxyl group, or a sulfogroup, particularly preferably a hydrogen atom, a halogen atom, a cyanogroup, a carboxyl group, or a sulfo group, and most preferably ahydrogen atom.

a₁₁ to a₁₄ each preferably represents 1 or 2, and particularlypreferably all of all to a₁₄ represent 1.

M represents a hydrogen atom, a metal element or oxide thereof,hydroxide or halide, particularly preferably Cu, Ni, Zn and Al, and mostpreferably Cu.

When a phthalocyanine dye represented by formula (II) is a water-solubledye, it is preferred to have an ionic hydrophilic group. The ionichydrophilic group includes a sulfo group, a carboxyl group, a phosphonogroup, and a quaternary ammonium group. As the ionic hydrophilic group,a carboxyl group, a phosphono group, and a sulfo group are preferred,and a carboxyl group and a sulfo group are particularly preferred. Thecarboxyl group, phosphono group and sulfo group may be in the state of asalt, and the examples of the counter ions for forming the salts includean ammonium ion, an alkali metal ion (e.g., a lithium ion, a sodium ionand a potassium ion), and an organic cation (a tetramethylammonium ion,a tetramethylguanidium ion and a tetramethylsulfonium ion). Of thecounter ions, alkali metal ions are preferred, and a lithium ion isparticularly preferred for being capable of increasing the solubility ofdye and the stability of ink.

It is preferred that at least two ionic hydrophilic groups are containedin one molecule of a phthalocyanine dye, and it is particularlypreferred that at least two sulfo group and/or carboxyl group arecontained.

With respect to the preferred combinations of the substituents of acompound represented by formula (II), a compound in which at least oneof various substituents is the above preferred group is preferred, acompound in which a greater number of various substituents are the abovepreferred groups is more preferred, and a compound in which all thesubstituents are the above preferred groups is most preferred.

It is preferred to introduce at least one electron attractive group,e.g., a sulfinyl group, a sulfonyl group or a sulfamoyl group, to everyfour benzene ring of phthalocyanine so that the σp value of all thesubstituents of phthalocyanine skeleton becomes 1.6 or more in total.

A Hammett's substitution constant σp-value is explained below briefly.Hammett's rule is a rule of thumb suggested by L. P. Hammett in 1935 toquantitatively discuss the influence of a substituent on the reaction orequilibrium of a benzene derivative, and the appropriateness of the ruleis now widely recognized. There are substitution constant σp value andam value obtained by Hammett's rule, and these values can be found in alarge literature, e.g., J. A. Dean compiled, Lange's Handbook ofChemistry, 12th Ed., McGraw Hill (1979), and Kagaku no Ryoiki (TheDomain of Chemistry), Extra Issue, No. 122, pp. 96 to 103, Mankodo(1979).

A phthalocyanine derivative represented by formula (I) is generally amixture of analogues inevitably different in the introducing position ofsubstituent Xn (n is from 1 to 4) and Ym (m is from 1 to 4) andintroducing number according to synthesis method, accordingly in manycases these mixtures of analogues are shown as statistic equalization bygeneral formula. The present inventors classified these mixtures ofanalogues into three kinds shown below, thereby found that a specificmixture was particularly preferred. That is, the mixture of analogues ofphthalocyanine dyes represented by formulae (I) and (II) is classifiedto the following three kinds based on the substitution positions anddefined.

-   (1) β-Position substitution type: A phthalocyanine dye having    specific substituents at 2- and/or 3-positions, 6- and/or    7-positions, 10- and/or 11-positions, and 14- and/or 15-positions.-   (2) α-Position substitution type: A phthalocyanine dye having    specific substituents at 1- and/or 4-positions, 5- and/or    8-positions, 9- and/or 12-positions, and 13- and/or 16-positions.-   (3) α,β-Position substitution type: A phthalocyanine dye having    specific substituents at 1- to 16-positions irregularly.

In the specification of the present invention, the above β-positionsubstitution type, α-position substitution type and α,β-positionsubstitution type are used in the explanation of the derivatives ofphthalocyanine dyes having different structures (in particular,different in substitution positions).

Phthalocyanine derivatives for use in the present invention can besynthesized by the methods described in, e.g., Shirai and Kobayashi,Phthalocyanine—Kagaku to Kino (Phthalocyanine—Chemistry and Functions),pp. 1 to 62, IPC Co., C. C. Leznoff and A. B. P. Lever,Phthalocyanines—Properties and Applications, pp. 1 to 54, VCH Co., orthe methods quoted therein or analogous methods, in combination.

As described in WO 00/17275, WO 00/08103, WO 00/08101, WO 98/41853 andJP-A-10-36471, a phthalocyanine compound represented by formula (I) foruse in the resent invention can be synthesized through sulfonation,sulfonyl chlorination and amidation reactions of an unsubstitutedphthalocyanine compound. In this case, not only sulfonation can occuranywhere of the phthalocyanine nucleus but the control of the number tobe sulfonated is difficult. Accordingly, when sulfo groups areintroduced on such reaction conditions, the position and number of sulfogroups introduced into the product formed cannot be specified, and amixture of analogues different in the number of substituents and thesubstitution positions is inevitably produced. Therefore, since thenumber of heterocyclic-substituted sulfamoyl groups and the substitutionpositions cannot be specified when the compound of the invention issynthesized by using this mixture as the raw material, the product isobtained as α,β-position mixed substitution type mixture in which somekinds of compounds differ in the number of substituents and thesubstitution positions from the compound suitable for the ink set of theinvention are contained.

As described above, if a great number of electron attractive groups suchas sulfamoyl groups are introduced into phthalocyanine nucleus,oxidation potential is made nobler and ozone resistance is increased.According to the above synthesizing method, mixture of a phthalocyaninedye containing less electron attractive groups, i.e., oxidationpotential is more base, cannot be avoided. Accordingly, for theimprovement of ozone resistance, it is more preferred to use asynthesizing method which suppresses the formation of a compound havingmore base oxidation potential.

A phthalocyanine compound represented by formula (II) of the presentinvention can be derived from a tetrasulfophthalocyanine compoundobtained by reacting a phthalonitrile derivative (Compound P)represented by the formula shown in the following scheme and/or adiiminoisoindoline derivative (Compound Q) with a metal derivativerepresented by formula (III), or by reacting a 4-sulfophthalonitrilederivative (Compound R) represented by the formula shown in thefollowing scheme with a metal derivative represented by formula (III).

In the above formulae, Xp corresponds to X₁₁, X₁₂, X₁₃ or X₁₄ in formula(II). Yq and Yq′ correspond to Y₁₁, Y₁₂, Y₁₃, Y₁₄, Y₁₅, Y₁₆, Y₁₇ or Y₁₈in formula (II). In Compound R, M′ represents a cation.

As the cations represented by M′, an alkali metal ion, e.g., Li, Na andK, or an organic cation, e.g., a triethylammonium ion or a pyridiniumion, are exemplified.M-(Y)_(d)  (III)

In formula (III), M has the same meaning as M in formulae (I) and (II),Y represents a monovalent or divalent ligand, e.g., a halogen atom, anacetate anion, acetylacetonate or oxygen, and d represents an integer of1 to 4.

That is, according to the above synthesizing method, desiredsubstituents can be introduced in a desired number. In particular, whenit is desired to introduce a great number of electron attractive groupsto make oxidation potential noble as in the present invention, the abovesynthesizing method is very excellent as compared with the method ofsynthesizing a phthalocyanine compound represented by formula (I) asdescribed above.

The thus-obtained phthalocyanine compound represented by formula (II)is, in general, a mixture of the following compounds represented byformulae (a)-1, (a)-2, (a)-3 or (a)-4 which are isomers at eachsubstitution position of Xp, i.e., β-position substitution type.

In the above synthesizing method, if absolutely the same compound isused as Xp, β-position substitution type phthalocyanine dye in whichX₁₁, X₁₂, X₁₃ and X₁₄ are completely the same substituents can beobtained. On the other hand, when different kinds of Xp are used incombination, a dye having the substituent of the same kind but partiallydifferent from each other, or a dye having substituents different fromeach other can be synthesized. Of the dyes represented by formula (II),these dyes having electron attractive groups different from each othercan adjust the solubility and aggregation of dye and storage stabilityof ink, therefore, particularly preferred.

In the present invention, it was found that the fact that oxidationpotential is nobler than 1.0 V (vs SCE), in every substitution type, isvery important for the improvement of fastness, and the greatness of theeffect was not at all expected from the prior art techniques. Further,the reason is unknown, β-position substitution type is apparentlysuperior to α, β-position mixed substitution type in hue, light fastnessand ozone resistance.

The specific examples of phthalocyanine dyes represented by formulae (I)and (II) (exemplified compounds I-1 to I-12 corresponding to formula(I), and exemplified compounds 101 to 190 corresponding to formula (II))are shown below, but the phthalocyanine dyes which are used in thepresent invention are not limited thereto.

In the following tables, specific examples of each group of (X₁, X₂),(Y₁₁, Y₁₂), (Y₁₃, Y₁₄), (Y₁₅, Y₁₆), (Y₁₇, Y₁₈) are not in order.

TABLE 14

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 101 Cu—SO₂—NH—CH₂—CH₂—SO₃Li —H —H, —H —H, —H —H, —H —H, —H 102 Cu

—H —Cl, —H —Cl, —H —Cl, —H —Cl, —H 103 Cu

—H —H, —H —H, —H —H, —H —H, —H 104 Cu

—H —H, —H —H, —H —H, —H —H, —H 105 Ni

—H —Cl, —H —Cl, —H —Cl, —H —Cl, —H 106 Cu—SO₂—NH—CH₂—CH₂—SO₂—NH—CH₂—COONa —CH —H, —H —H, —H —H, —H —H, —H 107 Cu

—H —H, —H —H, —H —H, —H —H, —H 108 Cu —SO₂—CH₂—CH₂—CH₂—SO₃Li —H —H, —H—H, —H —H, —H —H, —H 109 Cu —SO₂—CH₂—CH₂—CH₂—SO₃K —H —H, —H —H, —H —H,—H —H, —H 110 Cu —SO₂—(CH₂)₃—CO₂K —H —H, —H —H, —H —H, —H —H, —H

TABLE 15

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 111 Cu

—H —H, —H —H, —H —H, —H —H, —H 112 Cu

—SO₃Li —H, —H —H, —H —H, —H —H, —H 113 Cu

—H —H, —H —H, —H —H, —H —H, —H 114 Cu

—SO₃Li —H, —H —H, —H —H, —H —H, —H 115 Cu

—H —H, —H —H, —H —H, —H —H, —H 116 Cu

—H —H, —H —H, —H —H, —H —H, —H 117 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 16

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 118 Cu

—H —H, —H —H, —H —H, —H —H, —H 119 Cu

—H —H, —H —H, —H —H, —H —H, —H 120 Cu

—H —H, —H —H, —H —H, —H —H, —H 121 Cu

—H —H, —H —H, —H —H, —H —H, —H 122 Cu

—H —H, —H —H, —H —H, —H —H, —H 123 Cu —SO₂NH—C₈H₁₇(t) —H —H, —H —H, —H—H, —H —H, —H 124 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 17

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 125 Cu

—H —H, —H —H, —H —H, —H —H, —H 126 Cu

—H —H, —H —H, —H —H, —H —H, —H 127 Cu

—H —H, —H —H, —H —H, —H —H, —H 128 Zn

—CN —H, —H —H, —H —H, —H —H, —H 129 Cu

—H —Cl, —H —Cl, —H —Cl, —H —Cl, —H 130 Cu

—H —H, —H —H, —H —H, —H —H, —H 131 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 18

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 132 Cu

—H —H, —H —H, —H —H, —H —H, —H 133 Cu

—H —H, —H —H, —H —H, —H —H, —H 134 Cu

—H —H, —H —H, —H —H, —H —H, —H 135 Cu

—H —H, —H —H, —H —H, —H —H, —H 136 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 19

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 137 Cu

—H —H, —H —H, —H —H, —H —H, —H 138 Cu

—H —H, —H —H, —H —H, —H —H, —H 139 Cu

—Cl —H, —H —H, —H —H, —H —H, —H 140 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 20

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 141 Cu

—H —H, —H —H, —H —H, —H —H, —H 142 Cu

—H —H, —H —H, —H —H, —H —H, —H 143 Cu

—H —H, —H —H, —H —H, —H —H, —H 144 Cu

—H —H, —H —H, —H —H, —H —H, —H 145 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 21 In the table, introducing position of each substituent (Xp₁)and (Xp₂) in β-position substituent type is not in order.M—Pc(Xp₁)_(m)(Xp₂)_(n) No. M Xp₁ m Xp₂ n 146 Cu

3

1 147 Cu

3

1 148 Cu

3

1 149 Cu

2

2 150 Cu

3

1 151 Cu

3

1 152 Cu

2.5

1.5 153 Cu

2

2 154 Cu

3

1 155 Cu

2

2 156 Cu

3

1 157 Cu

2

2

TABLE 22 In the table, introducing position of each substituent (Xp₁)and (Xp₂) in β-position substituent type is not in order.M—Pc(Xp₁)_(m)(Xp₂)_(n) No. M Xp₁ m Xp₂ n 158 Cu

3

1 159 Cu

3

1 160 Cu

3

1 161 Cu

3

1 162 Cu

2

2 163 Cu

3

1 164 Cu

2

2 165 Cu

3

1 166 Cu

3

1 167 Cu

2.5

1.5 168 Cu

2

2 169 Cu

3

1 170 Cu

2

2

TABLE 23 In the table, introducing position of each substituent (Xp₁)and (Xp₂) in β-position substituent type is not in order.M—Pc(Xp₁)_(m)(Xp₂)_(n) No. M Xp₁ m Xp₂ n 171 Cu

3

1 172 Cu

2

2 173 Cu

2

2 174 Cu

3

1 175 Cu

2

2 176 Cu

3

1 177 Cu

2

1 178 Cu

3

1 179 Cu

2

2 180 Cu

3

1 181 Cu

3

1 182 Cu

2.5

1.5

TABLE 24 In the table, introducing position of each substituent (Xp₁)and (Xp₂) in β-position substituent type is not in order.M—Pc(Xp₁)_(m)(Xp₂)_(n) No. M Xp₁ m Xp₂ n 183 Cu

2

2 184 Cu

3

1 185 Cu

3

1 186 Cu

3

1 187 Cu

3

1 188 Cu

3

1 189 Cu

3

1 190 Cu

3

1

The structure of the phthalocyanine compound shown byM-Pc(Xp₁)_(m)(Xp₂)_(n) in Tables 21 to 24 is as follows:

(each independently, Xp₁=Xp₁ or Xp₂)

Phthalocyanine dye represented by formula (I) can be synthesizedaccording to the above patents. Phthalocyanine dye represented byformula (II) can be synthesized according to the methods disclosed inJP-A-2001-226275, JP-A-2001-96610, JP-A-2001-47013 and JP-A-2001-193638besides the above synthesizing methods. The starting materials, dyeintermediates and synthesizing route are not limited to these.

The things concerning the ink of the invention other than colorants,e.g., dyes and pigments, are described below.

The ink in the present invention can contain surfactants other than thecompound represented by formula (1).

By adding a compound represented by formula (1) and other surfactants,if necessary, to ink, the liquid properties of ink are adjusted, therebythe discharge stability of ink is improved, which has excellent effectin water resistance of image and prevention of blotting.

As such surfactants, anionic surfactants, e.g., sodium dodecylsulfate,sodium dodecyloxysulfonate, and sodium alkylbenzenesulfonate, cationicsurfactants, e.g., cetyl pyridinium chloride, trimethylcetylammoniumchloride, and tetrabutylammonium chloride, and nonionic surfactants,e.g., polyoxyethylene nonylphenyl ether, polyoxyethylene naphthyl ether,and polyoxyethylene octylphenyl ether can be exemplified. Nonionicsurfactants are particularly preferably used.

The content of surfactants is from 0.001 to 15 wt %, preferably from0.005 to 10 wt %, and more preferably from 0.01 to 5 wt %, based on theink.

The ink for ink jet of the invention can be prepared by dissolvingand/or dispersing the dye and surfactants in an aqueous medium. The“aqueous medium” in the invention is a medium obtained by addingadditives such as a wetting agent, a stabilizer and an antiseptic towater or a mixture of water and small amount of water-miscible organicsolvent.

In preparing an ink solution of the invention, in the case ofwater-soluble ink, it is preferred to dissolve an ink solution in water,and then various solvents and additives are added, dissolved and mixedto thereby make a homogeneous ink solution.

As the dissolving methods at this time, various dissolution methods canbe used, e.g., dissolution by stirring, dissolution by ultrasonicirradiation, and dissolution by penetration. Stirring method ispreferred of all. Various well-known stirring methods, e.g., flowstirring, reverse agitator, and stirring by dissolver using shear force,can be used. A stirring method utilizing the shear force with the bottomof a container can also be used.

The examples of water-miscible organic solvents which can be used in thepresent invention include alcohols (e.g., methanol, ethanol, propanol,isopropanol, butanol, isobutanol, sec-butanol, t-butanol, pentanol,hexanol, cyclohexanol and benzyl alcohol), polyhydric alcohols (e.g.,ethylene glycol, diethylene glycol, triethylene glycol, polyethyleneglycol, propylene glycol, dipropylene glycol, polypropylene glycol,butylene glycol, hexanediol, pentanediol, glycerol, hexanetriol andthioglycol), glycol derivatives (e.g., ethylene glycol monomethyl ether,ethylene glycol monoethyl ether, ethylene glycol monobutyl ether,diethylene glycol monomethyl ether, diethylene glycol monobutyl ether,propylene glycol monomethyl ether, propylene glycol monobutyl ether,dipropylene glycol monomethyl ether, triethylene glycol monomethylether, ethylene glycol diacetate, ethylene glycol monomethyl etheracetate, triethylene glycol monomethyl ether, triethylene glycolmonoethyl ether, and ethylene glycol monophenyl ether), amines (e.g.,ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine,N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine,diethylenetriamine, triethylenetetramine, polyethyleneimine andtetramethyl-propylenediamine), and other polar solvents (e.g.,formamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, sulforan, 2-pyrrolidone, N-methyl-2-pyrrolidone,N-vinyl-2-pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone,acetonitrile and acetone). These water-miscible organic solvents may beused in combination of two or more.

When the dye is a water-soluble dye, the ink of the present inventioncan be manufactured by dissolving the dye in a high boiling pointorganic solvent and then emulsifying and dispersing the dye in anaqueous medium.

The boiling point of the high boiling point organic solvents which areused in the present invention is 150° C. or more, and preferably 170° C.or more.

The examples of the high boiling point organic solvents include phthalicesters (e.g., dibutyl phthalate, dioctyl phthalate, dicyclohexylphthalate, di-2-ethylhexyl phthalate, decyl phthalate,bis(2,4-di-tert-amylphenyl) isophthalate, and bis(1,1-diethylpropyl)phthalate), phosphoric or phosphonic esters (e.g., diphenyl phosphate,triphenyl phosphate, tricresyl phosphate, 2-ethylhexyldiphenylphosphate, dioctylbutyl phosphate, tricyclohexyl phosphate,tri-2-ethylhexyl phosphate, tridecyl phosphate, anddi-2-ethylhexylphenyl phosphate), benzoic esters (e.g., 2-ethylhexylbenzoate, 2,4-dichlorobenzoate, dodecyl benzoate, and2-ethylhexyl-p-hydroxy benzoate), amides (e.g., N,N-diethyldodecanamideand N,N-diethyllaurylamide), alcohols or phenols (e.g., isostearylalcohol, and 2,4-di-tert-amyl-phenol), aliphatic esters (e.g.,dibutoxyethyl succinate, di-2-ethylhexyl succinate, 2-hexadecyltetradecanoate, tributyl citrate, diethyl azelate, isostearyl lactate,and trioctyl citrate), aniline derivatives (e.g.,N,N-dibutyl-2-butoxy-5-tert-octylaniline), chlorinated paraffins (e.g.,paraffins having a chlorine content of from 10 to 80%), trimesic esters(e.g., tributyl trimesate), dodecylbenzene, diisopropylnaphthalene,phenols (e.g., 2,4-di-tert-amylphenol, 4-dodecyloxyphenol,4-dodecyloxycarbonylphenol, and 4-(4-dodecyloxyphenylsulfonyl)phenol),carboxylic acids (e.g., 2-(2,4-di-tert-amylphenoxybutyric acid and2-ethoxyoctane-decanoic acid), and alkylphosphoric acids (e.g.,di-2-(ethylhexyl)phosphoric acid and diphenylphosphoric acid). The highboiling point organic solvents can be used in an amount of from 0.01 to3 times of the oil-soluble dye in a mass ratio, and preferably from 0.01to 1.0 time. When a high boiling point organic solvents are present,dyes and other non-volatile components are difficult to precipitate ondispersing in ink, and the stability of ink is improved and dischargestability can be ensured.

These high boiling point organic solvents may be used alone, or may beused as mixture of two or more (e.g., mixtures of tricresyl phosphateand dibutyl phthalate, trioctyl phosphate and di(2-ethylhexyl) sebacate,and dibutyl phthalate and poly(N-t-butylacrylamide)).

The examples of the high boiling point organic solvents other than theabove compounds which are used in the present invention and/or thesynthesis methods of these high boiling point organic solvents aredisclosed, e.g., in U.S. Pat. Nos. 2,322,027, 2,533,514, 2,772,163,2,835,579, 3,594,171, 3,676,137, 3,689,271, 3,700,454, 3,748,141,3,764,336, 3,765,897, 3,912,515, 3,936,303, 4,004,928, 4,080,209,4,127,413, 4,193,802, 4,207,393, 4,220,711, 4,239,851, 4,278,757,4,353,979, 4,363,873, 4,430,421, 4,430,422, 4,464,464, 4,483,918,4,540,657, 4,684,606, 4,728,599, 4,745,049, 4,935,321, 5,013,639,EP-A-276319, EP-A-286253, EP-A-289820, EP-A-309158, EP-A-309159,EP-A-309160, EP-A-509311, EP-A-510576, East German Patents 147,009, 157,147, 159, 573, 225,240A, British Patent 2,091,124A, JP-A-48-47335,JP-A-50-26530, JP-A-51-25133, JP-A-51-26036, JP-A-51-27921,JP-A-51-27922, JP-A-51-149028, JP-A-52-46816, JP-A-53-1520,JP-A-53-1521, JP-A-53-15127, JP-A-53-146622, JP-A-54-91325,JP-A-54-106228, JP-A-54-118246, JP-A-55-59464, JP-A-56-64333,JP-A-56-81836, JP-A-59-204041, JP-A-61-8461, JP-A-62-118345,JP-A-62-247364, JP-A-63-167357, JP-A-63-214744, JP-A-63-301941,JP-A-64-9452, JP-A-64-9454, JP-A-64-68745, JP-A-1-101543, JP-A-1-102454,JP-A-2-792, JP-A-2-4239, JP-A-2-43541, JP-A-4-29237, JP-A-4-30165,JP-A-4-232946 and JP-A-4-346338.

The high boiling point organic solvents are used in an amount of from0.01 to 3.0 times of the oil-soluble dye in a mass ratio, and preferablyfrom 0.01 to 1.0 time.

In the invention, oil-soluble dyes and high boiling point organicsolvents are emulsified and dispersed in an aqueous medium. Inemulsification-dispersion, a low boiling point organic solvent can beused in some cases from the viewpoint of an emulsifying property. Thelow boiling point organic solvent is an organic solvent having a boilingpoint of from about 30° C. to about 150° C. at atmospheric pressure. Forexample, esters (e.g., ethyl acetate, butyl acetate, ethyl propionate,beta-ethoxyethyl acetate and methyl Cellosolve acetate), alcohols (e.g.,isopropyl alcohol, n-butylalcohol and sec-butyl alcohol), ketones (e.g.,methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone), amides(e.g., dimethylformamide and N-methylpyrrolidone), and ethers (e.g.,tetrahydrofuran and dioxane) are preferably used as low boiling pointorganic solvents, but low boiling point organic solvents are not limitedto these compounds.

An oil phase comprising a dye dissolved in a high boiling point organicsolvent, and in certain circumstances, in a mixed solvent of a highboiling point organic solvent and a low boiling point organic solvent,is emulsified and dispersed in a water phase mainly comprising water, tothereby form minute oil droplets of oil phase. At this time, thelater-described additives, e.g., surfactants, wetting agents, dyestabilizers, emulsion stabilizers, antiseptics and antifungal agents,can be added to either one or both of a water phase and an oil phase,according to necessary.

A method of adding an oil phase to a water phase is generally performedas the emulsifying method, but a so-called phase reversal emulsifyingmethod of dripping a water phase to an oil phase can also be preferablyused. Further, when the azo dye for use in the present invention iswater-soluble and the additives are oil-soluble, the above emulsifyingmethod can also be used.

Various kinds of surfactants can be used in emulsification dispersion,such as anionic surfactants, e.g., fatty acid salts, alkyl sulfate,alkylbenzene sulfonate, alkylnaphthalene sulfonate, dialkylsulfosuccinate, alkyl phosphate, condensation products ofnaphthalenesulfonic acid and formalin, and polyoxyethylene alkylsulfate, and nonionic surfactants, e.g., polyoxyethylene alkyl ether,polyoxy-ethylene alkylaryl ether, polyoxyethylene fatty acid ester,sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester,polyoxyethylene alkylamine, glycerol fatty acid ester, andoxyethylene-oxypropylene block copolymer are preferably used. Further,SURFYNOLS (manufactured by Air Products & Chemicals), which is anacetylene-based polyoxyethylene oxide surfactant, is also preferablyused. Amine oxide type ampholytic surfactants, e.g.,N,N-dimethyl-N-alkylamine oxide, are also preferably used. In addition,the surfactants described in JP-A-59-157636, pp. 37 and 38, and ResearchDisclosure, No. 308119 (1989) can also be used.

Water-soluble polymers can be added in combination with the abovesurfactants for the purpose of stabilization just after emulsification.As such water-soluble polymers, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, polyacrylic acid, polyacrylamide andcopolymers of these polymers are preferably used. It is also preferredto use natural water-soluble polymers, e.g., polysaccharides, casein andgelatin. For the stabilization of the dispersion product of a dye,polyvinyl, polyurethane, polyester, polyamide, polyurea andpolycarbonate, which are substantially insoluble in an aqueous mediumand produced by the polymerization of acrylic esters, methacrylicesters, vinyl esters, acrylamides, methacrylamides, olefins, styrenes,vinyl ethers and acrylonitriles, can also be used in combination. It ispreferred for these polymers to contain —SO₃ ⁻ or —COO⁻. When thesepolymers substantially insoluble in an aqueous medium are used, the useamount is preferably 20 wt % or less of the high boiling point organicsolvent, and more preferably 10 wt % or less.

When water-base ink is manufactured by emulsifying and dispersing anoil-soluble dye and a high boiling point organic solvent, controllingthe particle size is particularly important. In forming an image by inkjet, it is essential to make the average particle size of ink small inorder to increase color purity and density. The average particle size ispreferably 1 μm or less, and more preferably from 5 to 100 nm, in volumeaverage particle size.

The volume average particle size and particle size distribution ofdispersed particles can be easily measured according to well-knownmethods, e.g., a static light scattering method, a dynamic lightscattering method, a centrifugal precipitation method, and the methoddescribed in Jikken Kagaku Koza (Lectures on Experimental Chemistry),4th Ed., pp. 417 and 418. For example, it can be easily measured with avolume average particle size meter on the market (e.g., Microtrack UPA,manufactured by Nikkiso Co., Ltd.) by diluting ink with distilled waterso that the particle concentration in the ink reaches from 0.1 to 1 wt%. The dynamic light scattering method making use of laser Dopplereffect is especially preferably used, since it is possible to measure tothe extent of small size particles.

A volume average particle size is an average particle size weighted bythe volume of particles, and this is a value obtained by multiplying thediameter of each particle in the aggregation of the particles by thevolume of each particle, and dividing the sum total of the thus-obtainedvalue of each particle by the total volume of the particles. A volumeaverage particle size is described in Soichi Muroi, Kobunshi Latex noKagaku (Chemistry of High Polymer Latex), p. 119, published by KobunshiKanko-Kai.

It has been found that the presence of coarse particles has a seriousinfluence upon printing performance. That is, discharge failure ordischarge unevenness of ink is caused due to clogging of a head nozzleby coarse particles or due to the formation of fouling even if the headdoes not clog, which greatly influences printing performance. Forpreventing this state of affairs from occurring, it is important tosuppress the numbers of particles having a particle size of 5 μm or moreto 10 or less and a particle size of 1 μm or more to 1,000 or less in 1μl of ink.

For removing these coarse particles, well-known centrifugal separationmethod and precision filtration method can be used. The separation maybe performed just after emulsification and separation or may beperformed after adding various additives, such as a wetting agent and asurfactant, to the emulsified and dispersed product and immediatelybefore charging the ink in an ink cartridge.

As the effective means to obtain a small average particle size free ofcoarse particles, mechanical emulsifiers can be used.

As emulsifiers, well-known apparatus, e.g., a simple stirrer, animpeller, and an in-line stirring system, a milling system, e.g., acolloid mill, and an ultrasonic wave system can be used, but a highpressure homogenizer is particularly preferably used.

With respect to high pressure homogenizers, the mechanisms are disclosedin detail in U.S. Pat. No. 4,533,254 and JP-A-6-47264. As commerciallyavailable pressure homogenizers, Gaulin Homogenizer (manufactured by A.P. V. Gaulin Inc.), Microfluidizer (manufactured by Microfluidex Inc.),and Ultimizer (manufactured by Sugino Machine Co., Ltd.) are known.

Further, as is disclosed in U.S. Pat. No. 5,720,551 in recent years, ahigh pressure homogenizer equipped with the mechanism of effectingatomization in a super high pressure jet current is especially effectivefor the emulsification dispersion of the present invention. As anexample of an emulsifier using a super high pressure jet current, De Bee2000 (Bee International Ltd.) is exemplified.

The pressure in performing emulsification with a high pressureemulsifying-dispersing apparatus is 50 PMa or more, preferably 60 MPa ormore, and more preferably 180 PMa or more.

It is particularly preferred to use a method of using two or moreemulsifiers in combination, e.g., by the method of emulsifying inkadditives with a stirring-emulsifier, and then emulsifying with a highpressure homogenizer. A method of once emulsifying ingredients withthese emulsifiers, adding ingredients, such as a wetting agent and asurfactant, and then passing the ink through a high pressure homogenizeragain while discharging the ink in a cartridge is also preferably used.

When a low boiling point organic solvent is used in addition to a highboiling point organic solvent, it is preferred to remove the low boilingpoint organic solvent from the viewpoint of the stability of anemulsified product and safety and hygiene. A variety of well-knownmethods can be used for removing low boiling point organic solvents inaccordance with the kinds of solvents, i.e., an evaporation method, avacuum evaporation method and an ultrafiltration method can be used. Aremoving process of a low boiling point organic solvent is preferablyperformed immediately after emulsification as soon as possible.

Manufacturing methods of inks for ink jet are disclosed in detail inJP-A-5-148436, JP-A-5-295312, JP-A-7-97541, JP-A-7-82515 andJP-A-7-118584, and these methods can be used in manufacturing the inkfor use in ink set for ink jet recording of the present invention.

The ink of the present invention can contain functional ingredients forimparting a variety of functions to the ink. As the functionalingredients, e.g., a drying inhibitor for preventing clogging of ink atan ink jet port due to drying, a penetration accelerator foraccelerating the penetration of ink into paper, an ultraviolet absorber,an antioxidant, a viscosity adjustor, a surface tension adjustor, adispersant, a dispersion stabilizer, an antifungal agent, a rustpreventive, a pH adjustor, a defoaming agent and a chelating agent areexemplified, and these functional ingredients can be selectedarbitrarily and used each in an appropriate amount.

As the drying inhibitors which are used in the present invention,water-soluble organic solvents having a lower vapor pressure than waterare preferred. The specific examples of drying inhibitors includepolyhydric alcohols represented by ethylene glycol, propylene glycol,diethylene glycol, polyethylene glycol, thiodiglycol, dithiodiglycol,2-methyl-1,3-propanediol, 1,2,6-hexanetriol, acetylene glycolderivatives, glycerol, and trimethylolpropane, lower alkyl ethers ofpolyhydric alcohols, e.g., ethylene glycol monomethyl (or ethyl) ether,diethylene glycol monomethyl (or ethyl) ether, and triethylene glycolmonoethyl (or butyl) ether, heterocyclic rings, e.g., 2-pyrrolidone,N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, andN-ethylmorpholine, sulfur-containing compounds, e.g., sulforan, dimethylsulfoxide and 3-sulforen, polyfunctional compounds, e.g., diacetonealcohol and diethanolamine, and urea derivatives. Of these compounds,polyhydric alcohols, such as glycerol and diethylene glycol are morepreferred. These drying inhibitors may be used alone or may be used incombination of two or more. Drying inhibitors are preferably used in anamount of from 10 to 50 wt % in the ink of the present invention.

As the penetration accelerators which are used in the present invention,alcohols, e.g., ethanol, isopropanol, butanol, di(tri)ethylene glycolmonobutyl ether, and 1,2-hexanediol, sodium lauryl sulfate, sodiumoleate, and nonionic surfactants can be used. Penetration acceleratorssufficiently show their effect when the amount of from 10 to 30 wt % iscontained in the ink of the present invention. The amount of penetrationaccelerators should be sufficient to prevent blotting of printing andprint through.

As the ultraviolet absorbers which are used in the present invention toimprove the storage stability of an image, the benzotriazole compoundsdisclosed in JP-A-58-185677, JP-A-61-190537, JP-A-2-782, JP-A-5-197075and JP-A-9-34057, the benzophenone compounds disclosed in JP-A-46-2784,JP-A-5-194483 and U.S. Pat. No. 3,214,463, the cinnamic acid compoundsdisclosed in JP-B-48-30492 (the term “JP-B” as used herein means an“examined Japanese patent publication”), JP-B-56-21141 andJP-A-10-88106, the triazine compounds disclosed in JP-A-4-298503,JP-A-8-53427, JP-A-8-239368, JP-A-10-182621, and JP-T-8-8-501291 (theterm “JP-T” as used herein means a published Japanese translation of aPCT patent application), the compounds described in Research Disclosure,No. 24239, and compounds which absorb ultraviolet rays and emitfluorescence represented by stilbene compounds and benzoxazolecompounds, i.e., a so-called fluorescent brightening agent, can be used.

As the antioxidants to improve the storage stability of an image,various kinds of organic series and metal complex series discolorationinhibitors can be used in the present invention. The examples of organicdiscoloration inhibitors include hydroquinones, alkoxyphenols,dialkoxyphenols, phenols, anilines, amines, indanes, chromans,alkoxyanilines and heterocyclic rings, and the examples of metal complexdiscoloration inhibitors include nickel complex and zinc complex. Morespecifically, the compounds described in Research Disclosure, No. 17643,items VII-I to J, ibid., No. 15162, ibid., No. 18716, p. 650, leftcolumn, ibid., No. 0.36544, p. 527, ibid., No. 307105, p. 872, andibid., No. 15162, and the compounds represented by formulae disclosed inJP-A-62-215272, pp. 127 to 137 and the exemplified compounds thereof canbe used.

As the antifungal agents which are used in the present invention, sodiumdehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, ethylp-hydroxybenzoate, 1,2-benzisothiazolin-3-one, and the salts thereof areexemplified. Antifungal agents are preferably used in an amount of from0.02 to 5.00 wt % in the ink of the present invention.

These compounds are described in detail in Bohkin Bohbai Zai Jiten(Thesaurus of Antibacterial and Antifungal Agents), compiled by NipponBohkin Bohbai Gakkai Thesaurus Compilation Committee.

As the rust preventives, e.g., acid sulfite, sodium thiosulfate, ammonthioglycolate, diisopropylammonium nitrite, pentaerythritoltetranitrate, dicyclohexylammonium nitrite, and benzotriazole areexemplified. Rust preventives are preferably used in an amount of from0.02 to 5.00 wt % in the ink of the present invention.

Other than the above surfactants, nonionic, cationic or anionicsurfactants are used as a surface tension adjustor. For example, asanionic surfactants, e.g., fatty acid salts, alkyl sulfate, alkylbenzenesulfonate, alkylnaphthalene sulfonate, dialkyl sulfosuccinate, alkylphosphate, condensation products of naphthalenesulfonic acid andformalin, and polyoxyethylene alkyl sulfate, and as nonionicsurfactants, e.g., polyoxyethylene alkyl ether, polyoxyethylenealkylaryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acidester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylenealkylamine, glycerol fatty acid ester, and oxyethylene-oxypropyleneblock copolymer are exemplified. Further, SURFYNOLS (manufactured by AirProducts & Chemicals), which is an acetylene-based polyoxyethylene oxidesurfactant, is also preferably used. Amine oxide type ampholyticsurfactants, e.g., N,N-dimethyl-N-alkylamine oxide, are also preferablyused. In addition, the surfactants described in JP-A-59-157636, pp. 37and 38, and Research Disclosure, No. 308119 (1989) can also be used.

The surface tension of the ink of the present invention is preferablyfrom 20 to 60 mN/m, and more preferably from 25 to 45 mN/m, with orwithout using a surface tension adjustor.

The viscosity of the ink in the invention is preferably 30 mPa·s orless. Since it is preferred to adjust the viscosity 20 mPa·s or less, aviscosity adjustor is sometimes used for the purpose of adjusting theviscosity. As viscosity adjustors, e.g., celluloses, water-solublepolymers, e.g., polyvinyl alcohol, and nonionic surfactants areexemplified. Viscosity adjustors are described in detail in Nendo ChoseiGijutsu (Techniques of Viscosity Adjustment), Chapter 9, Gijutsu JohoKyokai (1999), and Ink Jet Printer yo Chemicals (98 zoho)—Zairyo noKaihatsu Dohko•Tenbo Chosa (Chemicals for Ink Jet Printer (addition of98 new articles)—Development Trend of Materials and Research of theview), pp. 162 to 174, CMC Publishing Co. (1997).

In the present invention, various surfactants of the above-describedcationic, anionic and nonionic compounds can be used as a dispersant anda dispersion stabilizer, and chelating agents represented by fluorinecompounds, silicone compounds and EDTA can be used as a defoaming agent,if necessary.

A recording paper and a recording film used for image recording of thepresent invention are described below. The supports of a recording paperand a recording film comprise chemical pulp, e.g., LBKP and NBKP,mechanical pulp, e.g., GP, PGW, RMP, TMP, CTMP, CMP and CGP, and wastepaper pulp, e.g., DIP. Additives, e.g., well-known pigments, a binder, asize, a fixing agent, a cationic agent, and a paper strength reinforcingagent, are mixed with pulp according to necessity. Supports manufacturedby various apparatus, e.g., Fourdrinier machine and Yankee machine, canbe used in the present invention. Besides these supports, syntheticpaper and plastic film sheets can be used as supports. The thickness ofa support is preferably from 10 to 250 μm, and weighing is preferablyfrom 10 to 250 g/m².

A support may be directly provided with an image-receiving layer and aback coat layer to make an image-receiving material, or animage-receiving material may be produced by providing a size press andan anchor coat layer with starch and polyvinyl alcohol, and thenproviding an image-receiving layer and a back coat layer. A support maybe subjected to smoothing treatment by a calender, e.g., a machinecalender, a TG calender or a soft calender.

Paper and plastic films both surfaces of which are laminated withpolyolefin (e.g., polyethylene, polystyrene, polyethylene terephthalate,polybutene and copolymers of them) are more preferably used as supports.It is preferred to add a white pigment (e.g., titanium oxide and zincoxide) or a tinting dye (e.g., cobalt blue, ultramarine and neodymiumoxide) into polyolefin.

An image-receiving layer provided on a support contains a porousmaterial and an aqueous binder. An image-receiving layer preferablycontains a pigment, and a white pigment is preferred as the pigment. Theexamples of white pigments include inorganic white pigments, e.g.,calcium carbonate, kaolin, talc, clay, diatomaceous earth, syntheticamorphous silica, aluminum silicate, magnesium silicate, calciumsilicate, aluminum hydroxide, alumina, lithopone, zeolite, bariumsulfate, calcium sulfate, titanium dioxide, zinc sulfide, and zinccarbonate, and organic pigments, e.g., styrene series pigments, acrylicseries pigments, urea resins, and melamine resins. Porous inorganicwhite pigments are particularly preferred, and synthetic amorphoussilica having a great pore area is preferably used. Both silicicanhydride manufactured by a dry process and silicic hydrate manufacturedby a wet method can be used as synthetic amorphous silica, but it ispreferred to use silicic hydrate. Pigments may be used in combination oftwo or more.

As the aqueous binders contained in an image-receiving layer,water-soluble high polymers, e.g., polyvinyl alcohol, silanol-modifiedpolyvinyl alcohol, starch, cationic starch, casein, gelatin,carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl pyrrolidone,polyalkylene oxide, and polyalkylene oxide derivatives, andwater-dispersible high polymers, e.g., styrene-butadiene latex and anacrylic emulsion are exemplified. These aqueous binders may be usedalone or in combination of two or more. Of these binders, polyvinylalcohol and silanol-modified polyvinyl alcohol are preferably used inthe points of an adhering property to pigments and peeling resistance ofan ink-receptive layer.

In addition to pigments and aqueous binders, an image-receiving layercan contain a mordant, a waterproofing agent, a light fastness improver,a gas resistance improver, a surfactant, a hardening agent and otheradditives.

A mordant added to an image-receiving layer is preferably immobilized.For that sake, polymer mordants are preferably used.

Polymer mordants are disclosed in JP-A-48-28325, JP-A-54-74430,JP-A-54-124726, JP-A-55-22766, JP-A-55-142339, JP-A-60-23850,JP-A-60-23851, JP-A-60-23852, JP-A-60-23853, JP-A-60-57836,JP-A-60-60643, JP-A-60-118834, JP-A-60-122940, JP-A-60-122941,JP-A-60-122942, JP-A-60-235134, JP-A-1-161236, U.S. Pat. Nos. 2,484,430,2,548,564, 3,148,061, 3,309,690, 4,115,124, 4,124,386, 4,193,800,4,273,853, 4,282,305 and 4,450,224. The materials for image-receivinglayer containing the polymer mordants disclosed in JP-A-1-161236, pp.212 to 215 are particularly preferred. When the polymer mordantsdisclosed in the same patent are used, an image having excellent imagequality can be obtained and, further, the light fastness of the image isimproved.

A waterproofing agent is effective for waterproofing of an image, andcationic resins are especially preferably used as the waterproofingagent. The examples of the cationic resins include polyamide polyamineepichlorohydrin, polyethyleneimine, polyaminesulfone,dimethyldiallylammonium chloride polymers, cationic polyacrylamide andcolloidal silica, and polyamide-polyamine epichlorohydrin is preferredamong these cationic resins. These cationic resins are preferably usedin an amount of from 1 to 15 wt % based on the total solid content of anink-receiving layer, and particularly preferably from 3 to 10 wt %.

As a light fastness improver, zinc sulfate, zinc oxide, hindered amineantioxidants, and benzotriazole-based ultraviolet absorbers such asbenzophenone are exemplified, and zinc sulfate is preferably used.

Surfactants function as a coating assistant, a peeling improver, asliding improver or an antistatic agent. Surfactants are disclosed inJP-A-62-173463 and JP-A-62-183457.

Organic fluoro compounds may be used in place of surfactants. Organicfluoro compounds are preferably hydrophobic. The examples of organicfluoro compounds include fluorine surfactants, oily fluorine compounds(e.g., fluorine oil), and solid state fluorine compound resins (e.g.,tetrafluoroethylene resins). Organic fluoro compounds are disclosed inJP-B-57-9053 (columns from 8 to 17), JP-A-61-20994 and JP-A-62-135826.

As the hardening agents, materials disclosed in JP-A-1-161236, p. 222.

As other additives to be added to an image-receiving layer, a pigmentdispersant, a thickener, a defoaming agent, a dye, a fluorescentbrightening agent, an antiseptic, a pH adjustor, a matting agent and ahardening agent are exemplified. An ink-receptive layer may comprise onelayer or two layers.

A recording paper and a recording film may be provided with a back coatlayer, and a white pigment, an aqueous binder and other ingredients maybe added to a back coat layer.

As the white pigments which are added to a back coat layer, whiteinorganic pigments, e.g., light calcium carbonate, heavy calciumcarbonate, kaolin, talc, calcium sulfate, barium sulfate, titaniumdioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminumsilicate, diatomaceous earth, calcium silicate, magnesium silicate,synthetic amorphous silica, colloidal silica, colloidal alumina,pseudo-boehmite, aluminum hydroxide, alumina, lithopone, zeolite,hydrated halloysite, magnesium carbonate, and magnesium hydroxide, andwhite organic pigments, e.g., styrene series plastic pigments, acrylicseries plastic pigments, polyethylene, microcapsules, urea resins, andmelamine resins are exemplified.

As the aqueous binders to be contained in a back coat layer,water-soluble high polymers, e.g., styrene-maleate copolymers,styrene-acrylate copolymers, polyvinyl alcohol, silanol-modifiedpolyvinyl alcohol, starch, cationic starch, casein, gelatin,carboxymethyl cellulose, hydroxyethyl cellulose and polyvinylpyrrolidone, and water-dispersible high polymers, e.g.,styrene-butadiene latices and acrylic emulsions are exemplified. Asother ingredients to be added to a back coat layer, a defoaming agent, afoam inhibitor, a dye, a fluorescent brightening agent, an antiseptic,and a waterproofing agent are exemplified.

The constitutional layers of an ink jet recording paper and a recordingfilm (including a backing layer) may contain a dispersed product ofpolymer fine particles. A dispersed product of polymer fine particles isused for the purpose of improving physical properties of films, e.g.,the stabilization of dimension, prevention of curling, prevention ofadhesion, and prevention of film cracking. Dispersed products of polymerfine particles are disclosed in JP-A-62-245258, JP-A-62-136648 andJP-A-62-110066. Cracking and curling of a layer can be prevented byadding a dispersed product of polymer fine particles having a low glasstransition temperature (40° C. or lower) to a layer containing amordant. Curing can also be prevented by adding a dispersed product ofpolymer fine particles having a high glass transition temperature to abacking layer.

Ink jet recording methods are not restricted and used in well-knownsystems, e.g., a charge control system of discharging ink by making useof electrostatic induction, a drop-on-demand system (a pressure pulsesystem) by making use of oscillation pressure of a piezoid, an acousticink jet system of converting electric signals to acoustic beams tothereby irradiate ink, and discharging the ink by making use of thepressure of radiation, and a thermal ink jet (bubble jet) system ofheating ink to form bubbles, and discharging the ink by making use ofthe pressure generated.

Ink jet recording systems include a system of injecting ink calledphoto-ink having low density in a large number and in a small volume, asystem of improving image quality by using a plurality of inks havingsubstantially the same hue and different densities, and a system ofusing colorless and transparent ink.

In the present invention, the ink and ink set for ink jet recording, theconcentrated ink composition may be used in combination with the sheetfor the ink jet recroding of the present invention.

EXAMPLES

The present invention is described with reference to the examples below,but the present invention is not limited thereto.

In the examples, “parts” and “%” mean “parts by weight” and “weight %”,and “average molecular weight” and “polymerization degree” mean “averagemolecular weight by weight” and “average polymerization degree byweight”, unless otherwise indicated.

Manufacture of Support:

Wood pulp comprising 100 parts of LBKP was beaten by double disc refineruntil Canadian freeness 300 ml, and 0.5 part of epoxidized behenic acidamide, 1.0 part of anionic polyacrylamide, 0.1 part of polyamidepolyamine epichlorohydrin, and 0.5 part of cationic polyacrylamide wereadded to the pulp each in absolute dry mass ratio to the pulp, therebybase paper having a weight of 170 g/m² was made by a Fourdrinier.

For preparing the size for the surface of the above base paper, 0.04% ofa fluorescent brightening agent (Whitex BB, manufactured by SumitomoChemical Co., Ltd.) was added to a 4% aqueous solution of polyvinylalcohol, and the solution was impregnated into the base paper so as toreach 0.5 g/m² in terms of absolute dry mass. The base paper was dried,and then subjected to calendering treatment, thereby a substrate paperadjusted to a density of 1.05 g/ml was obtained.

After the wire side (rear side) of the obtained substrate paper wassubjected to corona discharge treatment, high density polyethylene wascoated on the rear side of the substrate paper with a melt extruder in athickness of 19 μm, thereby a resin layer having a matt face was formed(hereinafter, a resin layer side is referred to as “rear side”). Theresin layer of the rear side further underwent corona dischargetreatment, and a dispersion solution, as an antistatic agent, which wasobtained by dispersing aluminum oxide (Alumina Sol 100, manufactured byNissan Chemical Industries, Ltd.) and silicon dioxide (Snowtex O,manufactured by Nissan Chemical Industries, Ltd.) in water in a massratio of 1/2 was coated thereon in a dry mass of 0.2 g/m².

Further, the felt side (front side) of the substrate on which the resinlayer was not provided was subjected to corona discharge treatment, andthen low density polyethylene having MFR (melt flow rate) of 3.8 andcontaining 10% of anatase type titanium dioxide, a trace amount ofultramarine, and 0.01% (based on polyethylene) of a fluorescentbrightening agent was extruded with a melt extruder in a thickness of 29μm to form a highly glossy thermoplastic resin layer on the front sideof the substrate (hereinafter this highly glossy surface is referred toas “front side”), thereby a support was obtained.

Example 1

Preparation of Coating Solution a for Coloring Material-Receiving Layer

(1) Gas phase process silica fine particles, (2) ion exchange water, and(3) “PAS-M-1” in the composition shown below were mixed, and dispersedwith KD-P (a polymer, manufactured by Shinmaru Enterprises Corporation)at 10,000 rpm over 20 minutes, and then a solution containing (4)polyvinyl alcohol, (5) boric acid, (6) polyoxyethylene lauryl ether, and(7) ion exchange water, each shown below, was added to the abovedispersion, and the reaction mixture was further dispersed at 10,000 rpmover 20 minutes, thereby coating solution A for coloringmaterial-receiving layer was prepared.

The ratio by weight of the silica fine particles to the water-solubleresin (PB ratio: (1)/(4)) was 4.5/1, the pH of coating solution A forcoloring material-receiving layer was 3.5 of acid.

Composition of Coating Solution a for Coloring Material-Receiving Layer

(1) Gas phase process silica fine particles 10.0 parts Leoseal QS-30 (anaverage primary particle size: 7 nm, manufactured by TOKUYAMA Corp.) (2)Ion exchange water 51.7 parts (3) PAS-M-1 (a 60% aqueous solution, 0.83part a dispersant, manufactured by Nitto Boseki Co., Ltd.) (4) A 8%aqueous solution of polyvinyl alcohol 27.8 parts PVA 124 (awater-soluble resin, saponifica- tion degree: 98.5%, polymerizationdegree: 2,400, manufactured by KURARAY CO., LTD.) (5) Boric acid (acrosslinking agent) 0.4 part (6) Polyoxyethylene lauryl ether 1.2 partsEMULGEN 109P (a surfactant, a 10% aqueous solution, HLB value: 13.6,manufactured by Kao Corporation) (7) Ion exchange water 33.0 partsPreparation of Ink for Ink Jet Recording

After the front side of the above support was subjected to coronadischarge treatment, the above-prepared coating solution A for acoloring material-receiving layer was coated on the front side of thesupport with an extrusion die coater in a coating amount of 200 ml/m²(coating process), and the coated layer was subjected to drying with ahot air dryer at 80° C. and an air speed of 3 to 8 m/sec until the solidcontent concentration of the coated layer became 20%. The coated layershowed constant-rate drying speed during this period of time.Immediately after that, the support was immersed in mordant solution Bshown below for 30 seconds and 20 g/m² of mordant solution B was appliedon the coated layer (mordant solution application process), and thecoated layer further underwent drying at 80° C. for 10 minutes (dryingprocess). Thus, ink jet recording sheet R-1 provided with a coloringmaterial-receiving layer having a dry thickness of 32 μm of the presentinvention was obtained.

Composition of Mordant Coating Solution B

(1) Boric acid (a crosslinking agent) 0.65 part (2) Polyallylamine 25parts PAA-10C (a 10% aqueous solution, a mordant, manufactured by NittoBoseki Co., Ltd.) (3) Ion exchange water 59.7 parts (4) Ammoniumchloride (a surface pH adjustor) 0.8 part (5) Polyoxyethylene laurylether 10 parts EMULGEN 109P (a surfactant, a 2% aqueous solution, HLBvalue: 13.6, manufactured by Kao Corporation) (6) Megafac F1405 (a 10%aqueous solution, 2.0 parts a fluorine surfactant, manufactured byDainippon Chemicals and Ink Co., Ltd.)

Ink jet recording sheets R-2 to R-8 having the same composition with R-1respectively were prepared except for adding the additives shown inTable 25 below to R-1.

TABLE 25 Additive R-1 (Comparison) Not added R-2 (Comparison) 2.5 partsof POEP-1 to coating solution B of R-1 R-3 (Comparison) 2.5 parts ofPOEN-1 to coating solution B of R-1 R-4 (Invention) 2.5 parts of X-1 tocoating solution B of R-1 R-5 (Invention) 2.5 parts of X-3 to coatingsolution B of R-1 R-6 (Invention) 2.5 parts of X-7 to coating solution Bof R-1 R-7 (Invention) 2.5 parts of X-12 to coating solution B of R-1R-8 (Invention) 2.5 parts of X-14 to coating solution B of R-1 POEP-1:Polyoxyethylene nonylphenyl ether (PEO chain, average 30) POEN-1:Polyoxyethylene naphthyl ether (PEO chain, average 50)

Each of these ink jet recording sheet was charged in the paper feeder ofink jet printer PM-950C (manufactured by Epson Corporation), and amonochrome image of black was printed by using the ink set of PM-950C.Image fastness of the printed image under a high humidity condition wasevaluated.

Test for Evaluation:

A print pattern consisting of four square patterns of black of 3 cm×3 cmforming two lines with a white space of 1 mm wide intervening betweenfour square patterns was formed. After this image sample was stored at25° C., 90% RH for 72 hours, blotting of the black dye in the whitespace was observed. At the same time, the density of blotting in thewhite space was found by scanning each image with a scanningmicro-densitometer by setting the aperture of the micro-densitometer for0.3 mmφ. The light source of the micro-densitometer for photometry wasadjusted to spectral composition for measurement of visual density. Thevisual approximate density of the white ground to that just afterprinting of 0.01 or less was taken as A, from 0.01 to 0.05 as B, and0.05 or more was taken as C.

The results obtained are shown in Table 26 below.

TABLE 26 Blotting of Black Dye Genuine photographic paper PM CManufactured by Epson Corporation R-1 (Comparison) C R-2 (Comparison) CR-3 (Comparison) C R-4 (Invention) A R-5 (Invention) A R-6 (Invention) AR-7 (Invention) A R-8 (Invention) A

It was known from the results in Table 26 that the examples in which theink jet recording sheets of the present invention were used weresuperior to all the comparative examples in the point of blotting ofblack.

However, when the same experiment was performed by using the recordingsheets containing 2% of a non-reacted monomer of polyallylamine mordantPAA-10C, evaluation of blotting of R-4 to R-8 was B, every one of them.From this fact the effect of the present invention was confirmed.

When the ink jet recording sheet of the present invention having acoloring material-receiving layer comprising a mordant and a tertiary orquaternary amine compound containing at least one carboxyl group isused, the ink jet-recorded image obtained hardly blots even when theimage is stored under high humidity condition. Further, when images areoverprinted, blotting is not induced by the overprinted ink and anexcellent image quality can be maintained.

Example 3

Deionized water was added to the following ingredients to make thevolume of the solution one liter, and the solution was stirred at 30 to40° C. for one hour with heating. The solution was then filtered underreduced pressure through a microfilter having an average pore diameterof 0.25 μm, thereby Ink Solution LM-101 for light magenta was prepared.

Prescription of Light Magenta Ink LM-101:

Solid content Magenta dye shown below 7.5 g/liter (Exemplified Compounda-36) Urea 37 g/liter Liquid ingredients Diethylene glycol (DEG) 140g/liter Glycerol (GR) 120 g/liter Triethylene glycol monobutyl ether(TGB) 120 g/liter Triethanolamine (TEA) 6.9 g/liter Sarfinol STG (SW) 10g/liter

Ink Solution M-101 form agent a was prepared by increasing the amount ofmagenta dye (a-36) to 23 g in the above prescription.

Prescription of Magenta Ink M-101:

Solid content Magenta dye (a-36) 23 g/liter Urea 37 g/liter Liquidingredients Diethylene glycol (DEG) 140 g/liter Glycerol (GR) 120g/liter Triethylene glycol monobutyl ether (TGB) 120 g/literTriethaflolamine (TEA) 6.9 g/liter Sarfinol STG (SW) 10 g/liter

Inks LM-102 to 108, M-102 to 108 having the same composition with LM-101and M-101 respectively were prepared except for adding the ingredient asshown in Table 27 below to LM-101 and M-101.

TABLE 27 Sample No. Additive LM-101, M-101 (Comparison) None LM-102,M-102 (Comparison) 10 g/liter of POEP-1 to LM-101 and M-101 LM-103,M-103 (Comparison) 10 g/liter of POEN-1 to LM-101 and M-101 LM-104,M-104 (Invention) 10 g/liter of X-1 to LM-l01 and M-101 LM-105, M-105(Invention) 10 g/liter of X-3 to LM-101 and M-101 LM-106, M-106(Invention) 10 g/liter of X-7 to LM-101 and M-101 LM-107, M-107(Invention) 10 g/liter of X-10 to LM-101 and M-101 LM-108, M-108(Invention) 10 g/liter of X-14 to LM-101 and M-101 POEP-1:Polyoxyethylene nonylphenyl ether (PEO chain: about 30) POEN-1:Polyoxyethylene naphthyl ether (PEG chain: about 50)

Each of these inks was charged in cartridges of magenta ink and lightmagenta ink of ink jet printer PM-950C (manufactured by EpsonCorporation) The inks of PM-950C were used as inks of other colors, anda magenta monochrome image was printed. Ink jet paper photo-glossy paperEX (manufactured by Fuji Photo Film Co., Ltd.) was used as theimage-receiving sheet, on which an image was printed and image fastnessunder a high humidity condition was evaluated.

Experiment for Evaluation:

A print pattern consisting of four square patterns (reversal image) ofmagenta of 3 cm×3 cm forming two lines with a white space of 1 mm wideintervening between four square patterns crossing at right angles wasformed. After this image sample was stored at 25° C., 90% RH for 72hours, blotting of the magenta dye in the white space was observed. Atthe same time, the density of blotting (reflection density by status Agreen filter light) in the white space was found by scanning with ascanning micro-densitometer by setting the aperture of themicro-densitometer for 0.3 mmφ. The magenta density increase in thewhite space immediately after printing of 0.01 or less was taken as A,from 0.01 to 0.05 as B, and 0.05 or more was taken as C.

The results obtained are shown in Table 28 below.

TABLE 28 Sample No. Blotting of M Genuine Ink PM-950C B (manufac-turedby Epson Corporation) LM-101, M-101 (Comparison) C LM-102, M-102(Comparison) C LM-103, M-103 (Comparison) C LM-104, M-104 (Invention) ALM-105, M-105 (Invention) A LM-106, M-106 (Invention) A LM-107, M-107(Invention) A LM-108, M-108 (Invention) A

From the results in Table 28, it was found that the samples in which theink sets of the present invention were used were superior to all thecomparative samples in the point of blotting of magenta. In visualevaluation, too, blotting was not observed in every image of theinvention, and it was confirmed that the samples of the invention showedexcellent hue.

Example 4

Deionized water was added to the following ingredients to make thevolume of the solution one liter, and the solution was stirred at 30 to40° C. for one hour with heating. The solution was then filtered underreduced pressure through a microfilter having an average pore diameterof 0.25 μm, thereby Ink Solution LC-101 for light cyan was prepared.

Prescription of Light Cyan Ink LC-101:

Solid content Cyan dye (Exemplified Compound 154) 17.5 g/liter Proxel3.5 g/liter (2-benzisothiazolin-3-one) Liquid ingredients Diethyleneglycol 159 g/liter Glycerol 130 g/liter Triethylene glycol monobutylether 130 g/liter Triethanolamine 6.9 g/liter Sarfinol STG (SW: nonionicsurfactant) 10 g/liter

Ink Solution C-101 for cyan was prepared by increasing the amount ofcyan dye (Exemplified Compound 154) to 68 g in the above prescription.

Prescription of Cyan Ink C-101:

Solid content Cyan dye (Exemplified Compound 154) 68 g/liter Proxel 3.5g/liter (2-benzisothiazolin-3-one) Liquid ingredients Diethylene glycol150 g/liter Glycerol 130 g/liter Triethylene glycol monobutyl ether 130g/liter Triethanolamine 6.9 g/liter Sarfinol STG 10 g/liter

Inks LC-102 to 108, C-102 to 108 having the same composition with LC-101and C-101 respectively were prepared except for adding the ingredient asshown in Table 29 below to LC-101 and C-101.

TABLE 29 Sample No. Additive LC-101, C-101 (Comparison) None LC-102,C-102 (Comparison) 10 g/liter of POEP-1 to LC-101 and C-101 LC-103,C-103 (Comparison) 10 g/liter of POEN-1 to LC-101 and C-101 LC-104,C-104 (Invention) 10 g/liter of X-1 to LC-101 and C-101 LC-105, C-105(Invention) 10 g/liter of X-4 to LC-101 and C-101 LC-106, C-106(Invention) 10 g/liter of X-8 to LC-101 and C-101 LC-107, C-107(Invention) 10 g/liter of X-11 to LC-101 and C-101 LC-108, C-108(Invention) 10 g/liter of X-13 to LC-101 and C-101 POEP-1:Polyoxyethylene nonylphenyl ether (PEO chain: about 30) POEN-1:Polyoxyethylene naphthyl ether (PEO chain: about 50)

Each of these inks was charged in cartridges of cyan ink and light cyanink of ink jet printer PM-950C (manufactured by Epson Corporation), andevaluation was performed according to the same experimental method andevaluation criteria as in Example 3. Status A red filter light was usedin the measurement of density.

The results obtained are shown in Table 30 below.

TABLE 30 Sample No. Blotting of C Genuine Ink PM-950C B (manufactured byEpson Corporation) LC-101, C-101 (Comparison) C LC-102, C-102(Comparison) C LC-103, C-103 (Comparison) C LC-104, C-104 (Invention) ALC-105, C-105 (Invention) A LC-106, C-106 (Invention) A LC-107, C-107(Invention) A LC-108, C-108 (Invention) A

From the results in Table 30, it was found that the samples in which theink sets of the present invention were used were superior to all thecomparative samples in the point of blotting of cyan. That is, it wasshown that when the ink sets of the present invention were used, notonly the blotting of the ink itself recorded on the image-receivingsheet was prevented as shown in Example 1, but also the cyan and lightcyan inks on the image-receiving sheet effectively inhibited the actionof inducing blotting by the overprinted ink as shown in Example 2. Invisual evaluation, too, blotting was not observed in every image of theinvention, and it was confirmed that the samples of the invention showedexcellent hue.

The ink jet recording image formed by the ink jet ink of the inventioncomprising a dye, water, a water-soluble organic solvent and a carboxylgroup-containing tertiary or quaternary amine compound represented byformula (1) hardly generates blotting even under high humiditycondition, blotting by the overprinted ink is not induced whenoverprinted, and excellent image quality can be maintained.

The entire disclosure of each and every foreign patent application:Japanese Patent Application Nos. 2002-269170 and 2002-269171, from whichthe benefit of foreign priority has been claimed in the presentapplication is incorporated herein by reference, as if fully set forth.

1. An ink for ink jet recording, which comprises a dye, water, awater-miscible organic solvent and a compound represented by thefollowing formula (1):(R_(k))_(p)-N-[L_(m)-(COOM_(n))_(q)]_(r)  (1) wherein R represents analkyl group, an aryl group or a heterocyclic group; when a plural numberof R's are present, the plurality of R's may be the same or different;at least two of a plurality of R's may be linked with each other to forma cyclic structure; L represents a divalent or higher linking group; Mrepresents a hydrogen atom, an alkali metal cation, an ammonium ion, anorganic amine cation, or a negative ion sign; q and r each represents aninteger of 1 or more; k and m each represents 0 or an integer of 1 ormore; n represents an integer of 1 or more; p represents 0 or an integerof 1 or more; (p+r) is 3 or 4, when (p+r) is 4, the N atom represents aquaternary ammonium cation and one of the M's represents a negative ionsign, and wherein the dye includes a compound represented by thefollowing formula:

wherein A represents a 5-membered heterocyclic group; B¹ and B² eachrepresents a nitrogen atom, ═CR¹- or —CR²═, and when either one of B¹and B² represents a nitrogen atom, the other represents ═CR¹- or —CR²═;R⁵ and R⁶ each represents a hydrogen atom, an aliphatic group, anaromatic group, a heterocyclic group, an acyl group, an alkoxycarbonylgroup, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonylgroup, an arylsulfonyl group or a sulfamoyl group, and the hydrogen atomof each substituent may be substituted; G, R¹ and R² each independentlyrepresents a hydrogen atom, a halogen atom, an aliphatic group, anaromatic group, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, aheterocyclic oxycarbonyl group, an acyl group, a hydroxy group, analkoxy group, an aryloxy group, a heterocyclic oxy group, a silyloxygroup, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxygroup, an aryloxycarbonyloxy group, an amino group, an acylamino group,a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonylgroup, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclicsulfinyl group, a sulfamoyl group or a sulfo group, and the hydrogenatom of each substituent may be substituted; and R¹ and R⁵, or R⁵ and R⁶may combine to form a 5- or 6-membered ring.
 2. The ink for ink jetrecording as claimed in claim 1, wherein at least one of R and L informula (1) contains a hydrocarbon group having 8 or more carbon atoms.3. The ink for ink jet recording as claimed in claim 1, wherein thecompound represented by the formula (1) is a compound represented by thefollowing formula (2):R-N-(L-COOM)₂  (2) wherein R, L and M each has the same meaning asdescribed in claim
 1. 4. An ink for ink jet recording, which comprises adye, water, a water-miscible organic solvent and a compound representedby the following formula (2):R-N-(L-COOM)₂  (2) wherein R represents an alkyl group, an aryl group ora heterocyclic group; L represents a divalent or higher linking group;and M represents a hydrogen atom or an alkali metal cation, and pluralM's are different from each other and wherein the dye includes acompound represented by the following formula (I):

wherein X₁, X₂, X₃ and X₄ each represents —SO—Z, —SO₂—Z, —SO₂NR₁R₂, asulfo group, —CONR₁R₂ or —CO₂R₁; Z represents an alkyl group, acycloalkyl group, an alkenyl group, an aralkyl group, an aryl group or aheterocyclic group, which are substituted or unsubstituted; R₁ and R₂each represents a hydrogen atom, an alkyl group, a cycloalkyl group, analkenyl group, an aralkyl group, an aryl group or a heterocyclic group,which are substituted or unsubstituted; when a plural number of Z's arepresent, the plurality of Z's may be the same or different; Y₁, Y₂, Y₃and Y₄ each represents a monovalent substituent; when a plural number ofX₁'s, X₂'s, X₃'s, X₄'s, Y₁'s, Y₂'s, Y₃'s or Y₄'s are present, theplurality of X₁'s, X₂'s, X₃'s, X₄'s, Y₁'s, Y₂'s, Y₃'s or Y₄'s may be thesame or different; M represents a hydrogen atom, a metal atom, or anoxide, hydroxide or halide thereof; a₁ to a₄ and b₁ to b₄ eachrepresents the number of substituent X₁, X₂, X₃, X₄, Y₁, Y₂, Y₃ or Y₄,and a₁ to a₄ each represents an integer of 0 to 4 but all of a₁ to a₄are not 0 at the same time; and b₁ to b₄ each represents an integer of 0to
 4. 5. A concentrated ink composition comprising a dye, water, and acompound represented by the following formula (1):(R_(k))_(p)-N-[L_(m)-(COOM_(n))_(q)]_(r)  (1) wherein R represents analkyl group, an aryl group or a heterocyclic group; when a plural numberof R's are present, the plurality of R's may be the same or different;at least two of a plurality of R's may be linked with each other to forma cyclic structure; L represents a divalent or higher linking group; Mrepresents a hydrogen atom, an alkali metal cation, an ammonium ion, anorganic amine cation, or a negative ion sign; q and r each represents aninteger of 1 or more; k and m each represents 0 or an integer of 1 ormore; n represents an integer of 1 or more; p represents 0 or an integerof 1 or more; (p+r) is 3 or 4, and when (p+r) is 4, the N atomrepresents a quaternary ammonium cation and one of the M's represents anegative ion sign, and wherein the dye includes a compound representedby the following formula:

wherein A represents a 5-membered heterocyclic group; B¹ and B² eachrepresents a nitrogen atom, ═CR¹- or —CR²═, and when either one of B¹and B² represents a nitrogen atom, the other represents ═CR¹- or —CR²═;R⁵ and R⁶ each represents a hydrogen atom, an aliphatic group, anaromatic group, a heterocyclic group, an acyl group, an alkoxycarbonylgroup, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonylgroup, an arylsulfonyl group or a sulfamoyl group, and the hydrogen atomof each substituent may be substituted; G, R¹ and R² each independentlyrepresents a hydrogen atom, a halogen atom, an aliphatic group, anaromatic group, a heterocyclic group, a cyano group, a carboxyl group, acarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, aheterocyclic oxycarbonyl group, an acyl group, a hydroxy group, analkoxy group, an aryloxy group, a heterocyclic oxy group, a silyloxygroup, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxygroup, an aryloxycarbonyloxy group, an amino group, an acylamino group,a ureido group, a sulfamoylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, an alkylsulfonylamino group, anarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkylthio group, an arylthio group, a heterocyclic thio group,an alkylsulfonyl group, an arylsulfonyl group, a heterocyclic sulfonylgroup, an alkylsulfinyl group, an arylsulfinyl group, a heterocyclicsulfinyl group, a sulfamoyl group or a sulfo group, and the hydrogenatom of each substituent may be substituted; and R¹ and R⁵, or R⁵ and R⁶may combine to form a 5- or 6-membered ring.
 6. The concentrated inkcomposition as claimed in claim 5, which comprises the compoundrepresented by the formula (1) in an amount of from 0.001 to 30 wt %. 7.The concentrated ink composition as claimed in claim 5, which comprisesthe dye in an amount of from 0.01 to 50 wt %.
 8. A method formanufacturing an ink for ink jet recording, which comprisesmanufacturing the ink by using the concentrated ink composition asclaimed in claim
 5. 9. An ink set for ink jet recording, which comprisesthe ink for ink jet recording as claimed in claim
 1. 10. An ink jetrecording method which comprises recording an image by using the ink forink jet recording as claimed in claim 1 with an ink jet printer.
 11. Anink jet recording method which comprises recording an image by using theink set as claimed in claim 9 with an ink jet printer.
 12. Aconcentrated ink composition, comprising a dye, water and a compoundrepresented by the following formula (2):R-N-(L-COOM)₂  (2) wherein R represents an alkyl group, an aryl group ora heterocyclic group; L represents a divalent or higher linking group;and M represents a hydrogen atom or an alkali metal cation and pluralM's are different from each other.
 13. The concentrated ink compositionas claimed in claim 12, which comprises the compound represented byformula (2) in an amount of from 0.001 to 30 wt %.
 14. The concentratedink composition as claimed in claim 12, which comprises the dye in anamount of from 0.01 to 50 wt %.
 15. A method for manufacturing an inkfor ink jet recording, which comprises manufacturing the ink by usingthe concentrated ink composition as claimed in claim
 12. 16. An ink setfor ink jet recording, which comprises the ink for ink jet recording asclaimed in claim
 4. 17. An ink jet recording method, which comprisesrecording an image by using the ink for ink jet recording as claimed inclaim 4 with an ink jet printer.
 18. An ink jet recording method, whichcomprises recording an image by using the ink set as claimed in claim 16with an ink jet printer.